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I have two python files, the first python file which is triggered in server will dynamically fetch the variable result based on the environment the script is triggered . for an example , when script is triggered in dev environment. ideally, ${RPM_ENVIRONMENT} will return as 'DEV'
I have two files, one is my main file and one is my unit test cases
import os
import json
import subprocess
import logging
from os import listdir
from os.path import isfile, join
_ENV = os.popen("echo ${RPM_ENVIRONMENT}").read().split('\n')[0]
SERVER_URL = {
'DEV':{'ENV_URL':'https://dev.net'},
'UAT':{'ENV_URL':'https://uat.net'},
'PROD':{'ENV_URL':'https://prod.net'}
}[_ENV]
inside my test cases script below, i wanted to mimic as dev environment using unitest mock . i have tried below script but it was returning RPM_ENVIROMENT as key error .
test_env.py
import unittest , sys , tempfile, os , json , shutil
from unittest import mock
## i wanted to mock all the required variables before running import env_test so that it wont return any error.
with mock.patch.object(os, 'popen') as mock_popen:
sys.path.insert(1, 'C:/home/test/conf')
import env_test as conf
class test_tbrp_case(unittest.TestCase):
def test_port(self):
#function yet to be created
pass
if __name__=='__main__':
unittest.main()
I have tried using os.popen to mimic , but i am confused on how i can assign 'DEV' to _ENV variable .
when i tried to run this script, it was returning error as
SERVER_URL = {
KeyError: <MagicMock name='popen().read().split().__getitem__()' id='1893950325424'
**Approach 2 i have tried **
What i am trying to mock is the import , when im importing my main.py , it should dynamically replace/mock _ENV as 'DEV' , and SERVER_URL variable should automatically call Dev.
In a scenario where i call conf._ENV after i have implemented the mock below. it should return the value as "DEV"
def rpm_environment():
return os.popen("echo ${RPM_ENVIRONMENT}").read()
def test_rpm_environment():
with mock.patch("os.popen") as popen_mock:
popen_mock().read.return_value = "DEV"
actual = rpm_environment()
assert actual == "DEV"
## When i import env_test , RPM_ENVIROMENT wont be able to mock as DEV on what was declared in our test_rpm_enviromnet
rpm_environment()
test_rpm_environment()
# How can we safely import our env_test files with having variables been mocked so that i can call server_url variable
sys.path.insert(1, 'C:/home/test/conf')
import env_test import conf
I didn't quite understand if your code is inside a function or not.
If it is, the best way to do so is not patch.object. It's just a normal patch:
Consider this example:
def question():
return os.popen("what_ever").read()
def test_question():
with patch("os.popen") as popen_mock:
popen_mock().read.return_value = "DEV"
actual = question()
assert actual == "DEV"
In my opinion, patching os.popen and adding read to it's structure is the best practice.
Good luck !
When you mock popen it will return a MagickMock object and that object does not have a defined read response. You need to define what happens when someone calls read() on a MagickMock object that you have returned. Although it is not the most elegant solution, you can do this by adding this line in the with block:
mock_popen.return_value.read.return_value = "DEV"
This will instruct the MagickMock object to return the string "DEV" when read() is called on it.
How do I load a Python module given its full path?
Note that the file can be anywhere in the filesystem where the user has access rights.
See also: How to import a module given its name as string?
For Python 3.5+ use (docs):
import importlib.util
import sys
spec = importlib.util.spec_from_file_location("module.name", "/path/to/file.py")
foo = importlib.util.module_from_spec(spec)
sys.modules["module.name"] = foo
spec.loader.exec_module(foo)
foo.MyClass()
For Python 3.3 and 3.4 use:
from importlib.machinery import SourceFileLoader
foo = SourceFileLoader("module.name", "/path/to/file.py").load_module()
foo.MyClass()
(Although this has been deprecated in Python 3.4.)
For Python 2 use:
import imp
foo = imp.load_source('module.name', '/path/to/file.py')
foo.MyClass()
There are equivalent convenience functions for compiled Python files and DLLs.
See also http://bugs.python.org/issue21436.
The advantage of adding a path to sys.path (over using imp) is that it simplifies things when importing more than one module from a single package. For example:
import sys
# the mock-0.3.1 dir contains testcase.py, testutils.py & mock.py
sys.path.append('/foo/bar/mock-0.3.1')
from testcase import TestCase
from testutils import RunTests
from mock import Mock, sentinel, patch
To import your module, you need to add its directory to the environment variable, either temporarily or permanently.
Temporarily
import sys
sys.path.append("/path/to/my/modules/")
import my_module
Permanently
Adding the following line to your .bashrc (or alternative) file in Linux
and excecute source ~/.bashrc (or alternative) in the terminal:
export PYTHONPATH="${PYTHONPATH}:/path/to/my/modules/"
Credit/Source: saarrrr, another Stack Exchange question
If your top-level module is not a file but is packaged as a directory with __init__.py, then the accepted solution almost works, but not quite. In Python 3.5+ the following code is needed (note the added line that begins with 'sys.modules'):
MODULE_PATH = "/path/to/your/module/__init__.py"
MODULE_NAME = "mymodule"
import importlib
import sys
spec = importlib.util.spec_from_file_location(MODULE_NAME, MODULE_PATH)
module = importlib.util.module_from_spec(spec)
sys.modules[spec.name] = module
spec.loader.exec_module(module)
Without this line, when exec_module is executed, it tries to bind relative imports in your top level __init__.py to the top level module name -- in this case "mymodule". But "mymodule" isn't loaded yet so you'll get the error "SystemError: Parent module 'mymodule' not loaded, cannot perform relative import". So you need to bind the name before you load it. The reason for this is the fundamental invariant of the relative import system: "The invariant holding is that if you have sys.modules['spam'] and sys.modules['spam.foo'] (as you would after the above import), the latter must appear as the foo attribute of the former" as discussed here.
It sounds like you don't want to specifically import the configuration file (which has a whole lot of side effects and additional complications involved). You just want to run it, and be able to access the resulting namespace. The standard library provides an API specifically for that in the form of runpy.run_path:
from runpy import run_path
settings = run_path("/path/to/file.py")
That interface is available in Python 2.7 and Python 3.2+.
You can also do something like this and add the directory that the configuration file is sitting in to the Python load path, and then just do a normal import, assuming you know the name of the file in advance, in this case "config".
Messy, but it works.
configfile = '~/config.py'
import os
import sys
sys.path.append(os.path.dirname(os.path.expanduser(configfile)))
import config
I have come up with a slightly modified version of #SebastianRittau's wonderful answer (for Python > 3.4 I think), which will allow you to load a file with any extension as a module using spec_from_loader instead of spec_from_file_location:
from importlib.util import spec_from_loader, module_from_spec
from importlib.machinery import SourceFileLoader
spec = spec_from_loader("module.name", SourceFileLoader("module.name", "/path/to/file.py"))
mod = module_from_spec(spec)
spec.loader.exec_module(mod)
The advantage of encoding the path in an explicit SourceFileLoader is that the machinery will not try to figure out the type of the file from the extension. This means that you can load something like a .txt file using this method, but you could not do it with spec_from_file_location without specifying the loader because .txt is not in importlib.machinery.SOURCE_SUFFIXES.
I've placed an implementation based on this, and #SamGrondahl's useful modification into my utility library, haggis. The function is called haggis.load.load_module. It adds a couple of neat tricks, like the ability to inject variables into the module namespace as it is loaded.
You can use the
load_source(module_name, path_to_file)
method from the imp module.
Do you mean load or import?
You can manipulate the sys.path list specify the path to your module, and then import your module. For example, given a module at:
/foo/bar.py
You could do:
import sys
sys.path[0:0] = ['/foo'] # Puts the /foo directory at the start of your path
import bar
Here is some code that works in all Python versions, from 2.7-3.5 and probably even others.
config_file = "/tmp/config.py"
with open(config_file) as f:
code = compile(f.read(), config_file, 'exec')
exec(code, globals(), locals())
I tested it. It may be ugly, but so far it is the only one that works in all versions.
You can do this using __import__ and chdir:
def import_file(full_path_to_module):
try:
import os
module_dir, module_file = os.path.split(full_path_to_module)
module_name, module_ext = os.path.splitext(module_file)
save_cwd = os.getcwd()
os.chdir(module_dir)
module_obj = __import__(module_name)
module_obj.__file__ = full_path_to_module
globals()[module_name] = module_obj
os.chdir(save_cwd)
except Exception as e:
raise ImportError(e)
return module_obj
import_file('/home/somebody/somemodule.py')
If we have scripts in the same project but in different directory means, we can solve this problem by the following method.
In this situation utils.py is in src/main/util/
import sys
sys.path.append('./')
import src.main.util.utils
#or
from src.main.util.utils import json_converter # json_converter is example method
To add to Sebastian Rittau's answer:
At least for CPython, there's pydoc, and, while not officially declared, importing files is what it does:
from pydoc import importfile
module = importfile('/path/to/module.py')
PS. For the sake of completeness, there's a reference to the current implementation at the moment of writing: pydoc.py, and I'm pleased to say that in the vein of xkcd 1987 it uses neither of the implementations mentioned in issue 21436 -- at least, not verbatim.
I believe you can use imp.find_module() and imp.load_module() to load the specified module. You'll need to split the module name off of the path, i.e. if you wanted to load /home/mypath/mymodule.py you'd need to do:
imp.find_module('mymodule', '/home/mypath/')
...but that should get the job done.
You can use the pkgutil module (specifically the walk_packages method) to get a list of the packages in the current directory. From there it's trivial to use the importlib machinery to import the modules you want:
import pkgutil
import importlib
packages = pkgutil.walk_packages(path='.')
for importer, name, is_package in packages:
mod = importlib.import_module(name)
# do whatever you want with module now, it's been imported!
There's a package that's dedicated to this specifically:
from thesmuggler import smuggle
# À la `import weapons`
weapons = smuggle('weapons.py')
# À la `from contraband import drugs, alcohol`
drugs, alcohol = smuggle('drugs', 'alcohol', source='contraband.py')
# À la `from contraband import drugs as dope, alcohol as booze`
dope, booze = smuggle('drugs', 'alcohol', source='contraband.py')
It's tested across Python versions (Jython and PyPy too), but it might be overkill depending on the size of your project.
Create Python module test.py:
import sys
sys.path.append("<project-path>/lib/")
from tes1 import Client1
from tes2 import Client2
import tes3
Create Python module test_check.py:
from test import Client1
from test import Client2
from test import test3
We can import the imported module from module.
This area of Python 3.4 seems to be extremely tortuous to understand! However with a bit of hacking using the code from Chris Calloway as a start I managed to get something working. Here's the basic function.
def import_module_from_file(full_path_to_module):
"""
Import a module given the full path/filename of the .py file
Python 3.4
"""
module = None
try:
# Get module name and path from full path
module_dir, module_file = os.path.split(full_path_to_module)
module_name, module_ext = os.path.splitext(module_file)
# Get module "spec" from filename
spec = importlib.util.spec_from_file_location(module_name,full_path_to_module)
module = spec.loader.load_module()
except Exception as ec:
# Simple error printing
# Insert "sophisticated" stuff here
print(ec)
finally:
return module
This appears to use non-deprecated modules from Python 3.4. I don't pretend to understand why, but it seems to work from within a program. I found Chris' solution worked on the command line but not from inside a program.
I made a package that uses imp for you. I call it import_file and this is how it's used:
>>>from import_file import import_file
>>>mylib = import_file('c:\\mylib.py')
>>>another = import_file('relative_subdir/another.py')
You can get it at:
http://pypi.python.org/pypi/import_file
or at
http://code.google.com/p/import-file/
To import a module from a given filename, you can temporarily extend the path, and restore the system path in the finally block reference:
filename = "directory/module.py"
directory, module_name = os.path.split(filename)
module_name = os.path.splitext(module_name)[0]
path = list(sys.path)
sys.path.insert(0, directory)
try:
module = __import__(module_name)
finally:
sys.path[:] = path # restore
A simple solution using importlib instead of the imp package (tested for Python 2.7, although it should work for Python 3 too):
import importlib
dirname, basename = os.path.split(pyfilepath) # pyfilepath: '/my/path/mymodule.py'
sys.path.append(dirname) # only directories should be added to PYTHONPATH
module_name = os.path.splitext(basename)[0] # '/my/path/mymodule.py' --> 'mymodule'
module = importlib.import_module(module_name) # name space of defined module (otherwise we would literally look for "module_name")
Now you can directly use the namespace of the imported module, like this:
a = module.myvar
b = module.myfunc(a)
The advantage of this solution is that we don't even need to know the actual name of the module we would like to import, in order to use it in our code. This is useful, e.g. in case the path of the module is a configurable argument.
I have written my own global and portable import function, based on importlib module, for:
Be able to import both modules as submodules and to import the content of a module to a parent module (or into a globals if has no parent module).
Be able to import modules with a period characters in a file name.
Be able to import modules with any extension.
Be able to use a standalone name for a submodule instead of a file name without extension which is by default.
Be able to define the import order based on previously imported module instead of dependent on sys.path or on a what ever search path storage.
The examples directory structure:
<root>
|
+- test.py
|
+- testlib.py
|
+- /std1
| |
| +- testlib.std1.py
|
+- /std2
| |
| +- testlib.std2.py
|
+- /std3
|
+- testlib.std3.py
Inclusion dependency and order:
test.py
-> testlib.py
-> testlib.std1.py
-> testlib.std2.py
-> testlib.std3.py
Implementation:
Latest changes store: https://sourceforge.net/p/tacklelib/tacklelib/HEAD/tree/trunk/python/tacklelib/tacklelib.py
test.py:
import os, sys, inspect, copy
SOURCE_FILE = os.path.abspath(inspect.getsourcefile(lambda:0)).replace('\\','/')
SOURCE_DIR = os.path.dirname(SOURCE_FILE)
print("test::SOURCE_FILE: ", SOURCE_FILE)
# portable import to the global space
sys.path.append(TACKLELIB_ROOT) # TACKLELIB_ROOT - path to the library directory
import tacklelib as tkl
tkl.tkl_init(tkl)
# cleanup
del tkl # must be instead of `tkl = None`, otherwise the variable would be still persist
sys.path.pop()
tkl_import_module(SOURCE_DIR, 'testlib.py')
print(globals().keys())
testlib.base_test()
testlib.testlib_std1.std1_test()
testlib.testlib_std1.testlib_std2.std2_test()
#testlib.testlib.std3.std3_test() # does not reachable directly ...
getattr(globals()['testlib'], 'testlib.std3').std3_test() # ... but reachable through the `globals` + `getattr`
tkl_import_module(SOURCE_DIR, 'testlib.py', '.')
print(globals().keys())
base_test()
testlib_std1.std1_test()
testlib_std1.testlib_std2.std2_test()
#testlib.std3.std3_test() # does not reachable directly ...
globals()['testlib.std3'].std3_test() # ... but reachable through the `globals` + `getattr`
testlib.py:
# optional for 3.4.x and higher
#import os, inspect
#
#SOURCE_FILE = os.path.abspath(inspect.getsourcefile(lambda:0)).replace('\\','/')
#SOURCE_DIR = os.path.dirname(SOURCE_FILE)
print("1 testlib::SOURCE_FILE: ", SOURCE_FILE)
tkl_import_module(SOURCE_DIR + '/std1', 'testlib.std1.py', 'testlib_std1')
# SOURCE_DIR is restored here
print("2 testlib::SOURCE_FILE: ", SOURCE_FILE)
tkl_import_module(SOURCE_DIR + '/std3', 'testlib.std3.py')
print("3 testlib::SOURCE_FILE: ", SOURCE_FILE)
def base_test():
print('base_test')
testlib.std1.py:
# optional for 3.4.x and higher
#import os, inspect
#
#SOURCE_FILE = os.path.abspath(inspect.getsourcefile(lambda:0)).replace('\\','/')
#SOURCE_DIR = os.path.dirname(SOURCE_FILE)
print("testlib.std1::SOURCE_FILE: ", SOURCE_FILE)
tkl_import_module(SOURCE_DIR + '/../std2', 'testlib.std2.py', 'testlib_std2')
def std1_test():
print('std1_test')
testlib.std2.py:
# optional for 3.4.x and higher
#import os, inspect
#
#SOURCE_FILE = os.path.abspath(inspect.getsourcefile(lambda:0)).replace('\\','/')
#SOURCE_DIR = os.path.dirname(SOURCE_FILE)
print("testlib.std2::SOURCE_FILE: ", SOURCE_FILE)
def std2_test():
print('std2_test')
testlib.std3.py:
# optional for 3.4.x and higher
#import os, inspect
#
#SOURCE_FILE = os.path.abspath(inspect.getsourcefile(lambda:0)).replace('\\','/')
#SOURCE_DIR = os.path.dirname(SOURCE_FILE)
print("testlib.std3::SOURCE_FILE: ", SOURCE_FILE)
def std3_test():
print('std3_test')
Output (3.7.4):
test::SOURCE_FILE: <root>/test01/test.py
import : <root>/test01/testlib.py as testlib -> []
1 testlib::SOURCE_FILE: <root>/test01/testlib.py
import : <root>/test01/std1/testlib.std1.py as testlib_std1 -> ['testlib']
import : <root>/test01/std1/../std2/testlib.std2.py as testlib_std2 -> ['testlib', 'testlib_std1']
testlib.std2::SOURCE_FILE: <root>/test01/std1/../std2/testlib.std2.py
2 testlib::SOURCE_FILE: <root>/test01/testlib.py
import : <root>/test01/std3/testlib.std3.py as testlib.std3 -> ['testlib']
testlib.std3::SOURCE_FILE: <root>/test01/std3/testlib.std3.py
3 testlib::SOURCE_FILE: <root>/test01/testlib.py
dict_keys(['__name__', '__doc__', '__package__', '__loader__', '__spec__', '__annotations__', '__builtins__', '__file__', '__cached__', 'os', 'sys', 'inspect', 'copy', 'SOURCE_FILE', 'SOURCE_DIR', 'TackleGlobalImportModuleState', 'tkl_membercopy', 'tkl_merge_module', 'tkl_get_parent_imported_module_state', 'tkl_declare_global', 'tkl_import_module', 'TackleSourceModuleState', 'tkl_source_module', 'TackleLocalImportModuleState', 'testlib'])
base_test
std1_test
std2_test
std3_test
import : <root>/test01/testlib.py as . -> []
1 testlib::SOURCE_FILE: <root>/test01/testlib.py
import : <root>/test01/std1/testlib.std1.py as testlib_std1 -> ['testlib']
import : <root>/test01/std1/../std2/testlib.std2.py as testlib_std2 -> ['testlib', 'testlib_std1']
testlib.std2::SOURCE_FILE: <root>/test01/std1/../std2/testlib.std2.py
2 testlib::SOURCE_FILE: <root>/test01/testlib.py
import : <root>/test01/std3/testlib.std3.py as testlib.std3 -> ['testlib']
testlib.std3::SOURCE_FILE: <root>/test01/std3/testlib.std3.py
3 testlib::SOURCE_FILE: <root>/test01/testlib.py
dict_keys(['__name__', '__doc__', '__package__', '__loader__', '__spec__', '__annotations__', '__builtins__', '__file__', '__cached__', 'os', 'sys', 'inspect', 'copy', 'SOURCE_FILE', 'SOURCE_DIR', 'TackleGlobalImportModuleState', 'tkl_membercopy', 'tkl_merge_module', 'tkl_get_parent_imported_module_state', 'tkl_declare_global', 'tkl_import_module', 'TackleSourceModuleState', 'tkl_source_module', 'TackleLocalImportModuleState', 'testlib', 'testlib_std1', 'testlib.std3', 'base_test'])
base_test
std1_test
std2_test
std3_test
Tested in Python 3.7.4, 3.2.5, 2.7.16
Pros:
Can import both module as a submodule and can import content of a module to a parent module (or into a globals if has no parent module).
Can import modules with periods in a file name.
Can import any extension module from any extension module.
Can use a standalone name for a submodule instead of a file name without extension which is by default (for example, testlib.std.py as testlib, testlib.blabla.py as testlib_blabla and so on).
Does not depend on a sys.path or on a what ever search path storage.
Does not require to save/restore global variables like SOURCE_FILE and SOURCE_DIR between calls to tkl_import_module.
[for 3.4.x and higher] Can mix the module namespaces in nested tkl_import_module calls (ex: named->local->named or local->named->local and so on).
[for 3.4.x and higher] Can auto export global variables/functions/classes from where being declared to all children modules imported through the tkl_import_module (through the tkl_declare_global function).
Cons:
Does not support complete import:
Ignores enumerations and subclasses.
Ignores builtins because each what type has to be copied exclusively.
Ignore not trivially copiable classes.
Avoids copying builtin modules including all packaged modules.
[for 3.3.x and lower] Require to declare tkl_import_module in all modules which calls to tkl_import_module (code duplication)
Update 1,2 (for 3.4.x and higher only):
In Python 3.4 and higher you can bypass the requirement to declare tkl_import_module in each module by declare tkl_import_module in a top level module and the function would inject itself to all children modules in a single call (it's a kind of self deploy import).
Update 3:
Added function tkl_source_module as analog to bash source with support execution guard upon import (implemented through the module merge instead of import).
Update 4:
Added function tkl_declare_global to auto export a module global variable to all children modules where a module global variable is not visible because is not a part of a child module.
Update 5:
All functions has moved into the tacklelib library, see the link above.
This should work
path = os.path.join('./path/to/folder/with/py/files', '*.py')
for infile in glob.glob(path):
basename = os.path.basename(infile)
basename_without_extension = basename[:-3]
# http://docs.python.org/library/imp.html?highlight=imp#module-imp
imp.load_source(basename_without_extension, infile)
Import package modules at runtime (Python recipe)
http://code.activestate.com/recipes/223972/
###################
## #
## classloader.py #
## #
###################
import sys, types
def _get_mod(modulePath):
try:
aMod = sys.modules[modulePath]
if not isinstance(aMod, types.ModuleType):
raise KeyError
except KeyError:
# The last [''] is very important!
aMod = __import__(modulePath, globals(), locals(), [''])
sys.modules[modulePath] = aMod
return aMod
def _get_func(fullFuncName):
"""Retrieve a function object from a full dotted-package name."""
# Parse out the path, module, and function
lastDot = fullFuncName.rfind(u".")
funcName = fullFuncName[lastDot + 1:]
modPath = fullFuncName[:lastDot]
aMod = _get_mod(modPath)
aFunc = getattr(aMod, funcName)
# Assert that the function is a *callable* attribute.
assert callable(aFunc), u"%s is not callable." % fullFuncName
# Return a reference to the function itself,
# not the results of the function.
return aFunc
def _get_class(fullClassName, parentClass=None):
"""Load a module and retrieve a class (NOT an instance).
If the parentClass is supplied, className must be of parentClass
or a subclass of parentClass (or None is returned).
"""
aClass = _get_func(fullClassName)
# Assert that the class is a subclass of parentClass.
if parentClass is not None:
if not issubclass(aClass, parentClass):
raise TypeError(u"%s is not a subclass of %s" %
(fullClassName, parentClass))
# Return a reference to the class itself, not an instantiated object.
return aClass
######################
## Usage ##
######################
class StorageManager: pass
class StorageManagerMySQL(StorageManager): pass
def storage_object(aFullClassName, allOptions={}):
aStoreClass = _get_class(aFullClassName, StorageManager)
return aStoreClass(allOptions)
I'm not saying that it is better, but for the sake of completeness, I wanted to suggest the exec function, available in both Python 2 and Python 3.
exec allows you to execute arbitrary code in either the global scope, or in an internal scope, provided as a dictionary.
For example, if you have a module stored in "/path/to/module" with the function foo(), you could run it by doing the following:
module = dict()
with open("/path/to/module") as f:
exec(f.read(), module)
module['foo']()
This makes it a bit more explicit that you're loading code dynamically, and grants you some additional power, such as the ability to provide custom builtins.
And if having access through attributes, instead of keys is important to you, you can design a custom dict class for the globals, that provides such access, e.g.:
class MyModuleClass(dict):
def __getattr__(self, name):
return self.__getitem__(name)
In Linux, adding a symbolic link in the directory your Python script is located works.
I.e.:
ln -s /absolute/path/to/module/module.py /absolute/path/to/script/module.py
The Python interpreter will create /absolute/path/to/script/module.pyc and will update it if you change the contents of /absolute/path/to/module/module.py.
Then include the following in file mypythonscript.py:
from module import *
This will allow imports of compiled (pyd) Python modules in 3.4:
import sys
import importlib.machinery
def load_module(name, filename):
# If the Loader finds the module name in this list it will use
# module_name.__file__ instead so we need to delete it here
if name in sys.modules:
del sys.modules[name]
loader = importlib.machinery.ExtensionFileLoader(name, filename)
module = loader.load_module()
locals()[name] = module
globals()[name] = module
load_module('something', r'C:\Path\To\something.pyd')
something.do_something()
A quite simple way: suppose you want import file with relative path ../../MyLibs/pyfunc.py
libPath = '../../MyLibs'
import sys
if not libPath in sys.path: sys.path.append(libPath)
import pyfunc as pf
But if you make it without a guard you can finally get a very long path.
These are my two utility functions using only pathlib. It infers the module name from the path.
By default, it recursively loads all Python files from folders and replaces init.py by the parent folder name. But you can also give a Path and/or a glob to select some specific files.
from pathlib import Path
from importlib.util import spec_from_file_location, module_from_spec
from typing import Optional
def get_module_from_path(path: Path, relative_to: Optional[Path] = None):
if not relative_to:
relative_to = Path.cwd()
abs_path = path.absolute()
relative_path = abs_path.relative_to(relative_to.absolute())
if relative_path.name == "__init__.py":
relative_path = relative_path.parent
module_name = ".".join(relative_path.with_suffix("").parts)
mod = module_from_spec(spec_from_file_location(module_name, path))
return mod
def get_modules_from_folder(folder: Optional[Path] = None, glob_str: str = "*/**/*.py"):
if not folder:
folder = Path(".")
mod_list = []
for file_path in sorted(folder.glob(glob_str)):
mod_list.append(get_module_from_path(file_path))
return mod_list
This answer is a supplement to Sebastian Rittau's answer responding to the comment: "but what if you don't have the module name?" This is a quick and dirty way of getting the likely Python module name given a filename -- it just goes up the tree until it finds a directory without an __init__.py file and then turns it back into a filename. For Python 3.4+ (uses pathlib), which makes sense since Python 2 people can use "imp" or other ways of doing relative imports:
import pathlib
def likely_python_module(filename):
'''
Given a filename or Path, return the "likely" python module name. That is, iterate
the parent directories until it doesn't contain an __init__.py file.
:rtype: str
'''
p = pathlib.Path(filename).resolve()
paths = []
if p.name != '__init__.py':
paths.append(p.stem)
while True:
p = p.parent
if not p:
break
if not p.is_dir():
break
inits = [f for f in p.iterdir() if f.name == '__init__.py']
if not inits:
break
paths.append(p.stem)
return '.'.join(reversed(paths))
There are certainly possibilities for improvement, and the optional __init__.py files might necessitate other changes, but if you have __init__.py in general, this does the trick.
I have a dozen scripts where I'm repeating this
# caller.py
THIS_FILE_DIR = os.path.dirname(os.path.realpath(__file__))
relative_path = lambda *x: os.path.join(THIS_FILE_DIR, *x)
I'd like to move this into a module as follows:
# module.py
def relative_path(*x):
this_file_dir = os.path.dirname(os.path.realpath(__file__))
return os.path.join(this_file_dir, *x)
However I'd like to get __file__ in the scope of the calling script (caller.py) rather than the module (module.py) itself. Is there a way to do this without having the calling script pass in __file__ (so my relative_path() method only needs *x)?
It is not possible for an imported function to access global variables of the module where it [function] is imported.
relative_path() function can not access __file__ of caller.py.
You may pass it as a parameter:
def relative_path(*x, __file__):
this_file_dir = os.path.dirname(os.path.realpath(__file__))
return os.path.join(this_file_dir, *x)
It actually is possible. You can get path of caller like this
import inspect
def relative_path(*x):
caller_path = inspect.stack()[1].filename
You then have string of absolute path (recommend using pathlib instead of os if necessary)
Passing file is not necessary and can be confusing...
How do I load a Python module given its full path?
Note that the file can be anywhere in the filesystem where the user has access rights.
See also: How to import a module given its name as string?
For Python 3.5+ use (docs):
import importlib.util
import sys
spec = importlib.util.spec_from_file_location("module.name", "/path/to/file.py")
foo = importlib.util.module_from_spec(spec)
sys.modules["module.name"] = foo
spec.loader.exec_module(foo)
foo.MyClass()
For Python 3.3 and 3.4 use:
from importlib.machinery import SourceFileLoader
foo = SourceFileLoader("module.name", "/path/to/file.py").load_module()
foo.MyClass()
(Although this has been deprecated in Python 3.4.)
For Python 2 use:
import imp
foo = imp.load_source('module.name', '/path/to/file.py')
foo.MyClass()
There are equivalent convenience functions for compiled Python files and DLLs.
See also http://bugs.python.org/issue21436.
The advantage of adding a path to sys.path (over using imp) is that it simplifies things when importing more than one module from a single package. For example:
import sys
# the mock-0.3.1 dir contains testcase.py, testutils.py & mock.py
sys.path.append('/foo/bar/mock-0.3.1')
from testcase import TestCase
from testutils import RunTests
from mock import Mock, sentinel, patch
To import your module, you need to add its directory to the environment variable, either temporarily or permanently.
Temporarily
import sys
sys.path.append("/path/to/my/modules/")
import my_module
Permanently
Adding the following line to your .bashrc (or alternative) file in Linux
and excecute source ~/.bashrc (or alternative) in the terminal:
export PYTHONPATH="${PYTHONPATH}:/path/to/my/modules/"
Credit/Source: saarrrr, another Stack Exchange question
If your top-level module is not a file but is packaged as a directory with __init__.py, then the accepted solution almost works, but not quite. In Python 3.5+ the following code is needed (note the added line that begins with 'sys.modules'):
MODULE_PATH = "/path/to/your/module/__init__.py"
MODULE_NAME = "mymodule"
import importlib
import sys
spec = importlib.util.spec_from_file_location(MODULE_NAME, MODULE_PATH)
module = importlib.util.module_from_spec(spec)
sys.modules[spec.name] = module
spec.loader.exec_module(module)
Without this line, when exec_module is executed, it tries to bind relative imports in your top level __init__.py to the top level module name -- in this case "mymodule". But "mymodule" isn't loaded yet so you'll get the error "SystemError: Parent module 'mymodule' not loaded, cannot perform relative import". So you need to bind the name before you load it. The reason for this is the fundamental invariant of the relative import system: "The invariant holding is that if you have sys.modules['spam'] and sys.modules['spam.foo'] (as you would after the above import), the latter must appear as the foo attribute of the former" as discussed here.
It sounds like you don't want to specifically import the configuration file (which has a whole lot of side effects and additional complications involved). You just want to run it, and be able to access the resulting namespace. The standard library provides an API specifically for that in the form of runpy.run_path:
from runpy import run_path
settings = run_path("/path/to/file.py")
That interface is available in Python 2.7 and Python 3.2+.
You can also do something like this and add the directory that the configuration file is sitting in to the Python load path, and then just do a normal import, assuming you know the name of the file in advance, in this case "config".
Messy, but it works.
configfile = '~/config.py'
import os
import sys
sys.path.append(os.path.dirname(os.path.expanduser(configfile)))
import config
I have come up with a slightly modified version of #SebastianRittau's wonderful answer (for Python > 3.4 I think), which will allow you to load a file with any extension as a module using spec_from_loader instead of spec_from_file_location:
from importlib.util import spec_from_loader, module_from_spec
from importlib.machinery import SourceFileLoader
spec = spec_from_loader("module.name", SourceFileLoader("module.name", "/path/to/file.py"))
mod = module_from_spec(spec)
spec.loader.exec_module(mod)
The advantage of encoding the path in an explicit SourceFileLoader is that the machinery will not try to figure out the type of the file from the extension. This means that you can load something like a .txt file using this method, but you could not do it with spec_from_file_location without specifying the loader because .txt is not in importlib.machinery.SOURCE_SUFFIXES.
I've placed an implementation based on this, and #SamGrondahl's useful modification into my utility library, haggis. The function is called haggis.load.load_module. It adds a couple of neat tricks, like the ability to inject variables into the module namespace as it is loaded.
You can use the
load_source(module_name, path_to_file)
method from the imp module.
Do you mean load or import?
You can manipulate the sys.path list specify the path to your module, and then import your module. For example, given a module at:
/foo/bar.py
You could do:
import sys
sys.path[0:0] = ['/foo'] # Puts the /foo directory at the start of your path
import bar
Here is some code that works in all Python versions, from 2.7-3.5 and probably even others.
config_file = "/tmp/config.py"
with open(config_file) as f:
code = compile(f.read(), config_file, 'exec')
exec(code, globals(), locals())
I tested it. It may be ugly, but so far it is the only one that works in all versions.
You can do this using __import__ and chdir:
def import_file(full_path_to_module):
try:
import os
module_dir, module_file = os.path.split(full_path_to_module)
module_name, module_ext = os.path.splitext(module_file)
save_cwd = os.getcwd()
os.chdir(module_dir)
module_obj = __import__(module_name)
module_obj.__file__ = full_path_to_module
globals()[module_name] = module_obj
os.chdir(save_cwd)
except Exception as e:
raise ImportError(e)
return module_obj
import_file('/home/somebody/somemodule.py')
If we have scripts in the same project but in different directory means, we can solve this problem by the following method.
In this situation utils.py is in src/main/util/
import sys
sys.path.append('./')
import src.main.util.utils
#or
from src.main.util.utils import json_converter # json_converter is example method
To add to Sebastian Rittau's answer:
At least for CPython, there's pydoc, and, while not officially declared, importing files is what it does:
from pydoc import importfile
module = importfile('/path/to/module.py')
PS. For the sake of completeness, there's a reference to the current implementation at the moment of writing: pydoc.py, and I'm pleased to say that in the vein of xkcd 1987 it uses neither of the implementations mentioned in issue 21436 -- at least, not verbatim.
I believe you can use imp.find_module() and imp.load_module() to load the specified module. You'll need to split the module name off of the path, i.e. if you wanted to load /home/mypath/mymodule.py you'd need to do:
imp.find_module('mymodule', '/home/mypath/')
...but that should get the job done.
You can use the pkgutil module (specifically the walk_packages method) to get a list of the packages in the current directory. From there it's trivial to use the importlib machinery to import the modules you want:
import pkgutil
import importlib
packages = pkgutil.walk_packages(path='.')
for importer, name, is_package in packages:
mod = importlib.import_module(name)
# do whatever you want with module now, it's been imported!
There's a package that's dedicated to this specifically:
from thesmuggler import smuggle
# À la `import weapons`
weapons = smuggle('weapons.py')
# À la `from contraband import drugs, alcohol`
drugs, alcohol = smuggle('drugs', 'alcohol', source='contraband.py')
# À la `from contraband import drugs as dope, alcohol as booze`
dope, booze = smuggle('drugs', 'alcohol', source='contraband.py')
It's tested across Python versions (Jython and PyPy too), but it might be overkill depending on the size of your project.
Create Python module test.py:
import sys
sys.path.append("<project-path>/lib/")
from tes1 import Client1
from tes2 import Client2
import tes3
Create Python module test_check.py:
from test import Client1
from test import Client2
from test import test3
We can import the imported module from module.
This area of Python 3.4 seems to be extremely tortuous to understand! However with a bit of hacking using the code from Chris Calloway as a start I managed to get something working. Here's the basic function.
def import_module_from_file(full_path_to_module):
"""
Import a module given the full path/filename of the .py file
Python 3.4
"""
module = None
try:
# Get module name and path from full path
module_dir, module_file = os.path.split(full_path_to_module)
module_name, module_ext = os.path.splitext(module_file)
# Get module "spec" from filename
spec = importlib.util.spec_from_file_location(module_name,full_path_to_module)
module = spec.loader.load_module()
except Exception as ec:
# Simple error printing
# Insert "sophisticated" stuff here
print(ec)
finally:
return module
This appears to use non-deprecated modules from Python 3.4. I don't pretend to understand why, but it seems to work from within a program. I found Chris' solution worked on the command line but not from inside a program.
I made a package that uses imp for you. I call it import_file and this is how it's used:
>>>from import_file import import_file
>>>mylib = import_file('c:\\mylib.py')
>>>another = import_file('relative_subdir/another.py')
You can get it at:
http://pypi.python.org/pypi/import_file
or at
http://code.google.com/p/import-file/
To import a module from a given filename, you can temporarily extend the path, and restore the system path in the finally block reference:
filename = "directory/module.py"
directory, module_name = os.path.split(filename)
module_name = os.path.splitext(module_name)[0]
path = list(sys.path)
sys.path.insert(0, directory)
try:
module = __import__(module_name)
finally:
sys.path[:] = path # restore
A simple solution using importlib instead of the imp package (tested for Python 2.7, although it should work for Python 3 too):
import importlib
dirname, basename = os.path.split(pyfilepath) # pyfilepath: '/my/path/mymodule.py'
sys.path.append(dirname) # only directories should be added to PYTHONPATH
module_name = os.path.splitext(basename)[0] # '/my/path/mymodule.py' --> 'mymodule'
module = importlib.import_module(module_name) # name space of defined module (otherwise we would literally look for "module_name")
Now you can directly use the namespace of the imported module, like this:
a = module.myvar
b = module.myfunc(a)
The advantage of this solution is that we don't even need to know the actual name of the module we would like to import, in order to use it in our code. This is useful, e.g. in case the path of the module is a configurable argument.
I have written my own global and portable import function, based on importlib module, for:
Be able to import both modules as submodules and to import the content of a module to a parent module (or into a globals if has no parent module).
Be able to import modules with a period characters in a file name.
Be able to import modules with any extension.
Be able to use a standalone name for a submodule instead of a file name without extension which is by default.
Be able to define the import order based on previously imported module instead of dependent on sys.path or on a what ever search path storage.
The examples directory structure:
<root>
|
+- test.py
|
+- testlib.py
|
+- /std1
| |
| +- testlib.std1.py
|
+- /std2
| |
| +- testlib.std2.py
|
+- /std3
|
+- testlib.std3.py
Inclusion dependency and order:
test.py
-> testlib.py
-> testlib.std1.py
-> testlib.std2.py
-> testlib.std3.py
Implementation:
Latest changes store: https://sourceforge.net/p/tacklelib/tacklelib/HEAD/tree/trunk/python/tacklelib/tacklelib.py
test.py:
import os, sys, inspect, copy
SOURCE_FILE = os.path.abspath(inspect.getsourcefile(lambda:0)).replace('\\','/')
SOURCE_DIR = os.path.dirname(SOURCE_FILE)
print("test::SOURCE_FILE: ", SOURCE_FILE)
# portable import to the global space
sys.path.append(TACKLELIB_ROOT) # TACKLELIB_ROOT - path to the library directory
import tacklelib as tkl
tkl.tkl_init(tkl)
# cleanup
del tkl # must be instead of `tkl = None`, otherwise the variable would be still persist
sys.path.pop()
tkl_import_module(SOURCE_DIR, 'testlib.py')
print(globals().keys())
testlib.base_test()
testlib.testlib_std1.std1_test()
testlib.testlib_std1.testlib_std2.std2_test()
#testlib.testlib.std3.std3_test() # does not reachable directly ...
getattr(globals()['testlib'], 'testlib.std3').std3_test() # ... but reachable through the `globals` + `getattr`
tkl_import_module(SOURCE_DIR, 'testlib.py', '.')
print(globals().keys())
base_test()
testlib_std1.std1_test()
testlib_std1.testlib_std2.std2_test()
#testlib.std3.std3_test() # does not reachable directly ...
globals()['testlib.std3'].std3_test() # ... but reachable through the `globals` + `getattr`
testlib.py:
# optional for 3.4.x and higher
#import os, inspect
#
#SOURCE_FILE = os.path.abspath(inspect.getsourcefile(lambda:0)).replace('\\','/')
#SOURCE_DIR = os.path.dirname(SOURCE_FILE)
print("1 testlib::SOURCE_FILE: ", SOURCE_FILE)
tkl_import_module(SOURCE_DIR + '/std1', 'testlib.std1.py', 'testlib_std1')
# SOURCE_DIR is restored here
print("2 testlib::SOURCE_FILE: ", SOURCE_FILE)
tkl_import_module(SOURCE_DIR + '/std3', 'testlib.std3.py')
print("3 testlib::SOURCE_FILE: ", SOURCE_FILE)
def base_test():
print('base_test')
testlib.std1.py:
# optional for 3.4.x and higher
#import os, inspect
#
#SOURCE_FILE = os.path.abspath(inspect.getsourcefile(lambda:0)).replace('\\','/')
#SOURCE_DIR = os.path.dirname(SOURCE_FILE)
print("testlib.std1::SOURCE_FILE: ", SOURCE_FILE)
tkl_import_module(SOURCE_DIR + '/../std2', 'testlib.std2.py', 'testlib_std2')
def std1_test():
print('std1_test')
testlib.std2.py:
# optional for 3.4.x and higher
#import os, inspect
#
#SOURCE_FILE = os.path.abspath(inspect.getsourcefile(lambda:0)).replace('\\','/')
#SOURCE_DIR = os.path.dirname(SOURCE_FILE)
print("testlib.std2::SOURCE_FILE: ", SOURCE_FILE)
def std2_test():
print('std2_test')
testlib.std3.py:
# optional for 3.4.x and higher
#import os, inspect
#
#SOURCE_FILE = os.path.abspath(inspect.getsourcefile(lambda:0)).replace('\\','/')
#SOURCE_DIR = os.path.dirname(SOURCE_FILE)
print("testlib.std3::SOURCE_FILE: ", SOURCE_FILE)
def std3_test():
print('std3_test')
Output (3.7.4):
test::SOURCE_FILE: <root>/test01/test.py
import : <root>/test01/testlib.py as testlib -> []
1 testlib::SOURCE_FILE: <root>/test01/testlib.py
import : <root>/test01/std1/testlib.std1.py as testlib_std1 -> ['testlib']
import : <root>/test01/std1/../std2/testlib.std2.py as testlib_std2 -> ['testlib', 'testlib_std1']
testlib.std2::SOURCE_FILE: <root>/test01/std1/../std2/testlib.std2.py
2 testlib::SOURCE_FILE: <root>/test01/testlib.py
import : <root>/test01/std3/testlib.std3.py as testlib.std3 -> ['testlib']
testlib.std3::SOURCE_FILE: <root>/test01/std3/testlib.std3.py
3 testlib::SOURCE_FILE: <root>/test01/testlib.py
dict_keys(['__name__', '__doc__', '__package__', '__loader__', '__spec__', '__annotations__', '__builtins__', '__file__', '__cached__', 'os', 'sys', 'inspect', 'copy', 'SOURCE_FILE', 'SOURCE_DIR', 'TackleGlobalImportModuleState', 'tkl_membercopy', 'tkl_merge_module', 'tkl_get_parent_imported_module_state', 'tkl_declare_global', 'tkl_import_module', 'TackleSourceModuleState', 'tkl_source_module', 'TackleLocalImportModuleState', 'testlib'])
base_test
std1_test
std2_test
std3_test
import : <root>/test01/testlib.py as . -> []
1 testlib::SOURCE_FILE: <root>/test01/testlib.py
import : <root>/test01/std1/testlib.std1.py as testlib_std1 -> ['testlib']
import : <root>/test01/std1/../std2/testlib.std2.py as testlib_std2 -> ['testlib', 'testlib_std1']
testlib.std2::SOURCE_FILE: <root>/test01/std1/../std2/testlib.std2.py
2 testlib::SOURCE_FILE: <root>/test01/testlib.py
import : <root>/test01/std3/testlib.std3.py as testlib.std3 -> ['testlib']
testlib.std3::SOURCE_FILE: <root>/test01/std3/testlib.std3.py
3 testlib::SOURCE_FILE: <root>/test01/testlib.py
dict_keys(['__name__', '__doc__', '__package__', '__loader__', '__spec__', '__annotations__', '__builtins__', '__file__', '__cached__', 'os', 'sys', 'inspect', 'copy', 'SOURCE_FILE', 'SOURCE_DIR', 'TackleGlobalImportModuleState', 'tkl_membercopy', 'tkl_merge_module', 'tkl_get_parent_imported_module_state', 'tkl_declare_global', 'tkl_import_module', 'TackleSourceModuleState', 'tkl_source_module', 'TackleLocalImportModuleState', 'testlib', 'testlib_std1', 'testlib.std3', 'base_test'])
base_test
std1_test
std2_test
std3_test
Tested in Python 3.7.4, 3.2.5, 2.7.16
Pros:
Can import both module as a submodule and can import content of a module to a parent module (or into a globals if has no parent module).
Can import modules with periods in a file name.
Can import any extension module from any extension module.
Can use a standalone name for a submodule instead of a file name without extension which is by default (for example, testlib.std.py as testlib, testlib.blabla.py as testlib_blabla and so on).
Does not depend on a sys.path or on a what ever search path storage.
Does not require to save/restore global variables like SOURCE_FILE and SOURCE_DIR between calls to tkl_import_module.
[for 3.4.x and higher] Can mix the module namespaces in nested tkl_import_module calls (ex: named->local->named or local->named->local and so on).
[for 3.4.x and higher] Can auto export global variables/functions/classes from where being declared to all children modules imported through the tkl_import_module (through the tkl_declare_global function).
Cons:
Does not support complete import:
Ignores enumerations and subclasses.
Ignores builtins because each what type has to be copied exclusively.
Ignore not trivially copiable classes.
Avoids copying builtin modules including all packaged modules.
[for 3.3.x and lower] Require to declare tkl_import_module in all modules which calls to tkl_import_module (code duplication)
Update 1,2 (for 3.4.x and higher only):
In Python 3.4 and higher you can bypass the requirement to declare tkl_import_module in each module by declare tkl_import_module in a top level module and the function would inject itself to all children modules in a single call (it's a kind of self deploy import).
Update 3:
Added function tkl_source_module as analog to bash source with support execution guard upon import (implemented through the module merge instead of import).
Update 4:
Added function tkl_declare_global to auto export a module global variable to all children modules where a module global variable is not visible because is not a part of a child module.
Update 5:
All functions has moved into the tacklelib library, see the link above.
This should work
path = os.path.join('./path/to/folder/with/py/files', '*.py')
for infile in glob.glob(path):
basename = os.path.basename(infile)
basename_without_extension = basename[:-3]
# http://docs.python.org/library/imp.html?highlight=imp#module-imp
imp.load_source(basename_without_extension, infile)
Import package modules at runtime (Python recipe)
http://code.activestate.com/recipes/223972/
###################
## #
## classloader.py #
## #
###################
import sys, types
def _get_mod(modulePath):
try:
aMod = sys.modules[modulePath]
if not isinstance(aMod, types.ModuleType):
raise KeyError
except KeyError:
# The last [''] is very important!
aMod = __import__(modulePath, globals(), locals(), [''])
sys.modules[modulePath] = aMod
return aMod
def _get_func(fullFuncName):
"""Retrieve a function object from a full dotted-package name."""
# Parse out the path, module, and function
lastDot = fullFuncName.rfind(u".")
funcName = fullFuncName[lastDot + 1:]
modPath = fullFuncName[:lastDot]
aMod = _get_mod(modPath)
aFunc = getattr(aMod, funcName)
# Assert that the function is a *callable* attribute.
assert callable(aFunc), u"%s is not callable." % fullFuncName
# Return a reference to the function itself,
# not the results of the function.
return aFunc
def _get_class(fullClassName, parentClass=None):
"""Load a module and retrieve a class (NOT an instance).
If the parentClass is supplied, className must be of parentClass
or a subclass of parentClass (or None is returned).
"""
aClass = _get_func(fullClassName)
# Assert that the class is a subclass of parentClass.
if parentClass is not None:
if not issubclass(aClass, parentClass):
raise TypeError(u"%s is not a subclass of %s" %
(fullClassName, parentClass))
# Return a reference to the class itself, not an instantiated object.
return aClass
######################
## Usage ##
######################
class StorageManager: pass
class StorageManagerMySQL(StorageManager): pass
def storage_object(aFullClassName, allOptions={}):
aStoreClass = _get_class(aFullClassName, StorageManager)
return aStoreClass(allOptions)
I'm not saying that it is better, but for the sake of completeness, I wanted to suggest the exec function, available in both Python 2 and Python 3.
exec allows you to execute arbitrary code in either the global scope, or in an internal scope, provided as a dictionary.
For example, if you have a module stored in "/path/to/module" with the function foo(), you could run it by doing the following:
module = dict()
with open("/path/to/module") as f:
exec(f.read(), module)
module['foo']()
This makes it a bit more explicit that you're loading code dynamically, and grants you some additional power, such as the ability to provide custom builtins.
And if having access through attributes, instead of keys is important to you, you can design a custom dict class for the globals, that provides such access, e.g.:
class MyModuleClass(dict):
def __getattr__(self, name):
return self.__getitem__(name)
In Linux, adding a symbolic link in the directory your Python script is located works.
I.e.:
ln -s /absolute/path/to/module/module.py /absolute/path/to/script/module.py
The Python interpreter will create /absolute/path/to/script/module.pyc and will update it if you change the contents of /absolute/path/to/module/module.py.
Then include the following in file mypythonscript.py:
from module import *
This will allow imports of compiled (pyd) Python modules in 3.4:
import sys
import importlib.machinery
def load_module(name, filename):
# If the Loader finds the module name in this list it will use
# module_name.__file__ instead so we need to delete it here
if name in sys.modules:
del sys.modules[name]
loader = importlib.machinery.ExtensionFileLoader(name, filename)
module = loader.load_module()
locals()[name] = module
globals()[name] = module
load_module('something', r'C:\Path\To\something.pyd')
something.do_something()
A quite simple way: suppose you want import file with relative path ../../MyLibs/pyfunc.py
libPath = '../../MyLibs'
import sys
if not libPath in sys.path: sys.path.append(libPath)
import pyfunc as pf
But if you make it without a guard you can finally get a very long path.
These are my two utility functions using only pathlib. It infers the module name from the path.
By default, it recursively loads all Python files from folders and replaces init.py by the parent folder name. But you can also give a Path and/or a glob to select some specific files.
from pathlib import Path
from importlib.util import spec_from_file_location, module_from_spec
from typing import Optional
def get_module_from_path(path: Path, relative_to: Optional[Path] = None):
if not relative_to:
relative_to = Path.cwd()
abs_path = path.absolute()
relative_path = abs_path.relative_to(relative_to.absolute())
if relative_path.name == "__init__.py":
relative_path = relative_path.parent
module_name = ".".join(relative_path.with_suffix("").parts)
mod = module_from_spec(spec_from_file_location(module_name, path))
return mod
def get_modules_from_folder(folder: Optional[Path] = None, glob_str: str = "*/**/*.py"):
if not folder:
folder = Path(".")
mod_list = []
for file_path in sorted(folder.glob(glob_str)):
mod_list.append(get_module_from_path(file_path))
return mod_list
This answer is a supplement to Sebastian Rittau's answer responding to the comment: "but what if you don't have the module name?" This is a quick and dirty way of getting the likely Python module name given a filename -- it just goes up the tree until it finds a directory without an __init__.py file and then turns it back into a filename. For Python 3.4+ (uses pathlib), which makes sense since Python 2 people can use "imp" or other ways of doing relative imports:
import pathlib
def likely_python_module(filename):
'''
Given a filename or Path, return the "likely" python module name. That is, iterate
the parent directories until it doesn't contain an __init__.py file.
:rtype: str
'''
p = pathlib.Path(filename).resolve()
paths = []
if p.name != '__init__.py':
paths.append(p.stem)
while True:
p = p.parent
if not p:
break
if not p.is_dir():
break
inits = [f for f in p.iterdir() if f.name == '__init__.py']
if not inits:
break
paths.append(p.stem)
return '.'.join(reversed(paths))
There are certainly possibilities for improvement, and the optional __init__.py files might necessitate other changes, but if you have __init__.py in general, this does the trick.
In python is it possible to get or set a logical directory (as opposed to an absolute one).
For example if I have:
/real/path/to/dir
and I have
/linked/path/to/dir
linked to the same directory.
using os.getcwd and os.chdir will always use the absolute path
>>> import os
>>> os.chdir('/linked/path/to/dir')
>>> print os.getcwd()
/real/path/to/dir
The only way I have found to get around this at all is to launch 'pwd' in another process and read the output. However, this only works until you call os.chdir for the first time.
The underlying operational system / shell reports real paths to python.
So, there really is no way around it, since os.getcwd() is a wrapped call to C Library getcwd() function.
There are some workarounds in the spirit of the one that you already know which is launching pwd.
Another one would involve using os.environ['PWD']. If that environmnent variable is set you can make some getcwd function that respects it.
The solution below combines both:
import os
from subprocess import Popen, PIPE
class CwdKeeper(object):
def __init__(self):
self._cwd = os.environ.get("PWD")
if self._cwd is None: # no environment. fall back to calling pwd on shell
self._cwd = Popen('pwd', stdout=PIPE).communicate()[0].strip()
self._os_getcwd = os.getcwd
self._os_chdir = os.chdir
def chdir(self, path):
if not self._cwd:
return self._os_chdir(path)
p = os.path.normpath(os.path.join(self._cwd, path))
result = self._os_chdir(p)
self._cwd = p
os.environ["PWD"] = p
return result
def getcwd(self):
if not self._cwd:
return self._os_getcwd()
return self._cwd
cwd = CwdKeeper()
print cwd.getcwd()
# use only cwd.chdir and cwd.getcwd from now on.
# monkeypatch os if you want:
os.chdir = cwd.chdir
os.getcwd = cwd.getcwd
# now you can use os.chdir and os.getcwd as normal.
This also does the trick for me:
import os
os.popen('pwd').read().strip('\n')
Here is a demonstration in python shell:
>>> import os
>>> os.popen('pwd').read()
'/home/projteam/staging/site/proj\n'
>>> os.popen('pwd').read().strip('\n')
'/home/projteam/staging/site/proj'
>>> # Also works if PWD env var is set
>>> os.getenv('PWD')
'/home/projteam/staging/site/proj'
>>> # This gets actual path, not symlinked path
>>> import subprocess
>>> p = subprocess.Popen('pwd', stdout=subprocess.PIPE)
>>> p.communicate()[0] # returns non-symlink path
'/home/projteam/staging/deploys/20150114-141114/site/proj\n'
Getting the environment variable PWD didn't always work for me so I use the popen method. Cheers!