Cannot import script functions from another script - python

I've the following hierarchy:
.root
/program/main.py
/functions/myfunctions.py
And using my main.py I want to use the functions present in myfunctions.py script. For that I've defined my PYTHONPATH AS ./root/functions and I have this as the import on my script:
from functions import myfunctions as func
But I'm getting this error:
ModuleNotFoundError: No module named 'functions'
How can I solve this?
Thanks

You defined your PYTHONPATH as ./root/functions, so everything(modules/packages) "inside" that directory is recognizable by Python. ./root/functions directory is gonna get inserted to the sys.path. These paths are where Python loader checks to find modules and packages.
Just import the myfunctions.py:
import myfunctions as func
If you had defined PYTHONPATH as ./root, then you would have access to functions directory. (It became your namespace package for more information)

Import builtin module pathlib
Add the following code in your myfunctions.py
from pathlib import Path
Path(__file__).resolve().parent.parent

Related

Using a folder for personal modules in Python

I have created a folder named C:\Python27\Lib\site-packages\perso and inside I have put a file mymodule.py. The goal is to have this module accessible from any future Python script.
Let's do a D:\My Documents\test.py file:
import mymodule #fails
import perso.mymodule #fails
Why does it fail? How to import a module from C:\Python27\Lib\site-packages\perso? What are the best practice for using user-modules in all Python scripts of the same computer?
check PythonPath
create __init__.py to use perso as package
Python Modules:
In order to create a module you can do the following:
under <Python_DIR>\Lib\site-packages:
put you directory <module>. This directory contains your classes.
In <Python_DIR>\Lib\site-packages\<module> put an init file __init__.py,
This file define what's in the directory, and may apply some logic if needed.
for example:
__all__ = ["class_1", "class_2",].
Than, to import:
from <your_module> import <your_class>
For more information, read this.

Importing from relative path in python syntax error

I am trying to import from relative path in my python program.
the class i would like to import is in
home/foo/bar/model.py
However, my current python script is in
home/best/user/test.py
i have tried to use
from ../../foo/bar import class
But it throws up a syntax error
When importing modules, python looks in the current working directory and in the paths in sys.path. You can add the directory of the script you would like to import to sys.path:
import sys
sys.path.append('home/foo/bar')
import model # imports home/foo/bar/model.py
You can't do that. You can't import from an explicitly specified path (without awful trickery). All Python imports are based on the systemwide import paths (in sys,path). You can't import anything that isn't reachable from sys,path (i.e., it's either on sys.path itself or it's inside a package that's on sys.path). The documenation has the details. If you want to be able to import from that file, you need to somehow add its directory (or the directory of its topmost containing package) to the path.

Python Import Module

Recently started a new Python project.
I am resolving a import module error where I am trying to import modules from the same directory.
I was following the solutions here but my situation is slightly different and as a result my script cannot run.
My project directory is as follows:
dir-parent
->dir-child-1
->dir-child-2
->dir-child-3
->__init__.py (to let python now that I can import modules from here)
->module1
->module2
->module3
->module4
->main.py
In my main.py script I am importing these module in the same directory as follows:
from dir-parent.module1 import class1
When I run the script using this method it throws a import error saying that there is no module named dir-parent.module1 (which is wrong because it exists).
I then change the import statement to:
from module1 import class1
and this seemed to resolve the error, however, the code I am working on has been in use for over 2.5 years and it has always imported modules via this method, plus in the code it refers to the dir-parent directory.
I was just wondering if there is something I am missing or need to do to resolve this without changing these import statements and legacy code?
EDIT: I am using PyCharm and am running off PyCharm
If you want to keep the code unchanged, I think you will have to add dir-parent to PYTHONPATH. For exemple, add the following on top of your main.py :
import os, sys
parent_dir = os.path.abspath(os.path.dirname(__file__)) # get parent_dir path
sys.path.append(parent_dir)
Python's import and pathing are a pain. This is what I do for modules that have a main. I don't know if pythonic at all.
# Add the parent directory to the path
CURRENTDIR = os.path.dirname(os.path.dirname(os.path.realpath(__file__)))
if CURRENTDIR not in sys.path:
sys.path.append(CURRENTDIR)

trying to import a *.pyc as a module

I have a python script that is trying to import another script somewhere in the file-system (path is only known at runtime).
To my understanding I need to use the imp module and this might work, but when loading the module I get an error that modules used by the imported module are not found.
Heres the code:
importer.py:
import imp
imp.load_compiled("my_module","full_path_to_my_module\\my_module.pyc")
my_module.py:
import sys
import another_module
When I run importer.py I get htis error message:
ImportError: No module named another_module
Whats going wrong here ?
I suspect that when 'importer.py' is loading 'my_module.pyc' hes also trying to load 'another_module' (thats good) but is looking in the wrong place (eg not 'full_path_to_my_module')
EDIT:
I tried adding 'full_path_to_my_module' to the system path:
import imp
import sys
sys.path.append(full_path_to_my_module)
imp.load_compiled("my_module",full_path_to_my_module+my_module)
But I still get the same error
Maybe I do something thats not necessary - Here's my goal:
I want to be able to use all functionality of 'my_module.pyc' inside 'importer.py'. But the location of 'my_module.pyc' is given as a parameter to 'importer.py'.
imp.load_compiled returns the compiled module object, it is different to the import statement which also binds the module to a name
import imp
my_module = imp.load_compiled("my_module", "full_path_to_my_module/my_module.pyc")
Then you can do something like:
my_module.yayfunctions('a')
Complete example session:
$ cat /tmp/my_module.py
def yayfunctions(a):
print a
$ python -m compileall /tmp/my_module.py
$ ls /tmp/my_module.py*
my_module.py my_module.pyc
$ python
>>> import imp
>>> my_module = imp.load_compiled("my_module", "/tmp/my_module.pyc")
>>> my_module.yayfunctions('a')
a
Edit regarding comment (ImportError: No module named another_module), I assume the error is caused by the code in my_module.pyc, and the another_module.py lives in the same directory
In that case, as others have suggested, it's simpler to just add the directory containing my_module to sys.path and use the regular import mechanism, specifically __import__
Here's a function which should do what you want:
import os
def load_path(filepath):
"""Given a path like /path/to/my_module.pyc (or .py) imports the
module and returns it
"""
path, fname = os.path.split(filepath)
modulename, _ = os.path.splitext(fname)
if path not in sys.path:
sys.path.insert(0, path)
return __import__(modulename)
if __name__ == '__main__':
# Example usage
my_module = load_path('/tmp/my_module.py')
my_module.yayfunctions('test')
It is since at the scope of import another_module your "full_path_to_my_module" isn't known.
Have you tried to add the path to known paths instead, i.e.:
import sys
sys.path.append("full_path_to_my_module")
You don't actually need to use the imp module to load pyc modules.
An easy way to try it out is to make two python modules, one importing from the other and run it. Delete then the imported .py file so you only get the .pyc file left: when running the script the import will work just fine.
But, for importing py files from random directories, you may want to add that directory to the python path first before importing it.
For instance:
import sys
sys.path.insert(0, "/home/user/myrandomdirectory")
Loading pyc files works the exact same way as loading a py file except it doesn't do a compile step. Thus just using import mymodule will work as long as the version number of the pyc is the same as the python you're running. Otherwise you'll get a magic number error.
If you module isn't in your path you'll need to add that to sys -- or if its a subdirectory, add a __init__.py file to that directory..

Import python module NOT on path

I have a module foo, containing util.py and bar.py.
I want to import it in IDLE or python session. How do I go about this?
I could find no documentation on how to import modules not in the current directory or the default python PATH.
After trying import "<full path>/foo/util.py",
and from "<full path>" import util
The closest I could get was
import imp
imp.load_source('foo.util','C:/.../dir/dir2/foo')
Which gave me Permission denied on windows 7.
One way is to simply amend your path:
import sys
sys.path.append('C:/full/path')
from foo import util,bar
Note that this requires foo to be a python package, i.e. contain a __init__.py file. If you don't want to modify sys.path, you can also modify the PYTHONPATH environment variable or install the module on your system. Beware that this means that other directories or .py files in that directory may be loaded inadvertently.
Therefore, you may want to use imp.load_source instead. It needs the filename, not a directory (to a file which the current user is allowed to read):
import imp
util = imp.load_source('util', 'C:/full/path/foo/util.py')
You could customize the module search path using the PYTHONPATH environment variable, or manually modify the sys.path directory list.
See Module Search Path documentation on python.org.
Give this a try
import sys
sys.path.append('c:/.../dir/dir2')
import foo
Following phihag's tip, I have this solution. Just give the path of a source file to load_src and it will load it. You must also provide a name, so you can import this module using this name. I prefer to do it this way because it's more explicit:
def load_src(name, fpath):
import os, imp
return imp.load_source(name, os.path.join(os.path.dirname(__file__), fpath))
load_src("util", "../util.py")
import util
print util.method()
Another (less explicit) way is this:
util = load_src("util", "../util.py") # "import util" is implied here
print util.method() # works, util was imported by the previous line
Edit: the method is rewritten to make it clearer.

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