__init__.py files are meant to initialize packages and/or to set what directory is a package, as far as I know.
So my question is, even though these are implicitly run when a package/module is imported, is it normal to receive errors when you run that __init__.py file directly? and why?
I was testing a project I'm currently working on, which is working great, no errors when I import from root files, but what got my attention is that when I execute every module just to check for errors, all the __init__.py files are the ones that throws errors.
For the sake of education,
I followed these 'tutorials' and ran every __init__.py files of every package (directly, not importing a module/package) just to identify if I'm doing something wrong and received errors on those too.
Please, take a look at these examples:
Article: Understanding Python imports, __init__.py and pythonpath — once and for all
Traceback (most recent call last):
File "c:\Users\username\Desktop\python_packages_tutorial\utils\__init__.py", line 1, in <module>
from utils.lower import to_lower
ModuleNotFoundError: No module named 'utils'
I even added the directory to PYTHONPATH env variable, and sys.path even recognizes the directory where it is located. As I said before, it's just happening when I directly execute the init.py file, the rest is working well.
Article: Introduction to Create Own Python Packages
Traceback (most recent call last):
File "c:\Users\username\Desktop\medium_python_packages\my_package\__init__.py", line 1, in <module>
from .my_module1 import *
^^^^^^^^^^^^^^^^^^^^^^^^^
ImportError: attempted relative import with no known parent package
My project __init__.py file:
sys.path
[
'c:\\Users\\username\\Desktop\\code\\projects\\flask_app\\register',
'C:\\Users\\username\\Desktop\\code\\projects\\flask_app\\register', <-- PYTHONPATH env
'C:\\Users\\username\\AppData\\Local\\Programs\\Python\\Python311\\python311.zip',
'C:\\Users\\username\\AppData\\Local\\Programs\\Python\\Python311\\DLLs',
'C:\\Users\\username\\AppData\\Local\\Programs\\Python\\Python311\\Lib',
'C:\\Users\\username\\AppData\\Local\\Programs\\Python\\Python311',
'c:\\Users\\username\\Desktop\\code\\projects\\flask_app\\flask',
'c:\\Users\\username\\Desktop\\code\\projects\\flask_app\\flask\\Lib\\site-packages'
]
Traceback
Traceback (most recent call last):
File "c:\Users\username\Desktop\code\projects\flask_app\register\__init__.py", line 10, in <module>
from register.routes import *
ModuleNotFoundError: No module named 'register'
But they are working as expected.
Related
I have a project folder that has a module called 'src' containing my code. Within 'src', there is another module called 'crawlers' which has python code in it. In one of the files stored in the 'crawlers' folder, I call an import from the 'src' folder to get variables from its init.py file.
The structure is like this
└───src (this is a module)
├───crawlers (this is a module)
|----- code.py
├───datafiles
├───models
└───utils
in the code.py file I have
import json
from src import variable1, variable 2
When the code runs in vscode, I get this
Traceback (most recent call last):
File "d:/Code files/tech projects/tree_courses_scraper/src/crawlers/course_grab.py", line 2, in <module>
from src import umanitoba_calendar, umanitoba_codes
ModuleNotFoundError: No module named 'src'
I have been using pycharm community for a while and I never got this problem.
I have seen here, here and here but still not sure how to fix it.
I am doing my dev work on my Mac using PyCharm and everything works and imports.
When I take this project directory to FreeBSD jail. It fails to load internal directory code. and gives the following error:
Traceback (most recent call last):
File "project/src/my_script.py", line 3, in <module>
from src.auth import MyClient
ModuleNotFoundError: No module named 'src'
I am trying to execute the file my_script.py which imports src.auth.py
My Directory structure looks like this:
project
/src
__init__.py
my_script.py
auth.py
__init__.py
.env
both __init.py__ are empty files. Any help would be appreciated.
thanks
Why am I getting import error for a module I have in the project. All the packages are under the project, they all have __init __.py and other scripts do not give the same error. Python version is 3.6. Code was written in Unix environment.
Here is the import error I get. I am trying to run a test here.
Ran 1 test in 0.001s
FAILED (errors=1)
Error
Traceback (most recent call last):
File "/usr/lib/python3.6/unittest/case.py", line 59, in testPartExecutor
yield
File "/usr/lib/python3.6/unittest/case.py", line 605, in run
testMethod()
File "/usr/lib/python3.6/unittest/loader.py", line 34, in testFailure
raise self._exception
ImportError: Failed to import test module: test_SMSHandler
Traceback (most recent call last):
File "/usr/lib/python3.6/unittest/loader.py", line 153, in loadTestsFromName
module = __import__(module_name)
File "/home/sevvalboylu/server/app/api/test_SMSHandler.py", line 11, in <module>
from middleware.services import Sender
ModuleNotFoundError: No module named 'middleware'
Looks like you are missing a project's root path in PYTHONPATH
From the docs (Modules - The Module Source Path)
When a module named spam is imported, the interpreter first searches
for a built-in module with that name. If not found, it then searches
for a file named spam.py in a list of directories given by the
variable sys.path. sys.path is initialized from these locations:
The directory containing the input script (or the current directory
when no file is specified).
PYTHONPATH (a list of directory names, with the same syntax as the shell variable PATH).
The installation-dependent default.
If this solution doesn't work for you, please post the project's tree to make it easier find the problem.
I've experienced a similar problem with import error when running unit tests (with correct importable structure), but the cause and the solution are different to described in the answer above. Still this is relevant and may help somebody.
In my case I have structure like that (__init__.py present but omitted below for brevity):
mypkg
\-- foo.py
another
tests
\-- some
\-- <tests here>
mypkg <--- same name as top level module mypkg
\-- test_a.py
When running from top level directory imports in test_a.py of modules from mypkg were failing:
# test_a.py
from mypkg import foo # causes ModuleNotFoundError: No module named 'mypkg.foo'
Renaming mypkg folder under tests folder into something else solved the problem.
I have read a ton of stackoverflow answers and a bunch of tutorials. In addition, I tried to read the Python documentation, but I cannot make this import work.
This is how the directory looks like:
myDirectory
├── __init__.py
├── LICENSE
├── project.py
├── README.md
├── stageManager.py
└── tests
├── __init__.py
└── test_project.py
There is a class in project.py called Project, and I want to import it in a file under tests directory. I have tried the following:
Relative import:
from ..project import Project
def print_sth():
print("something")
This gives me the following error: (running from the tests directory as python test_project.py and from myDirectory as python tests/test_project.py)
Traceback (most recent call last):
File "test_project.py", line 1, in <module>
from ..project import Project
SystemError: Parent module '' not loaded, cannot perform relative import
Absolute import with package name:
If I have something like the following, I get ImportError (with the same run command as above).
from project import Project
def print_sth():
print("something")
------------------------------------------------------
Traceback (most recent call last):
File "test_project.py", line 1, in <module>
from project import Project
ImportError: No module named 'project'
and this too:
from myDirectory.project import Project
def print_sth():
print("something")
------------------------------------------------------
Traceback (most recent call last):
File "test_project.py", line 1, in <module>
from myDirectory.project import Project
ImportError: No module named 'myDirectory'
Finally, I tried adding the if __name__ == '__main__' statement within the test_project.py file, but it still failed. I would really appreciate if anyone could help. If there is a solution where I do not have to write a verbose command, I would prefer that.
When you run a Python script by filename, the Python interpreter assumes that it is a top-level module (and it adds the directory the script is in to the module search path). If the script is in a package, that's not correct. Instead, you should run the module using the -m flag, which takes a module name in the same format as an import statement (dotted separators) and puts the current directory in the module search path.
So, you could run the test from myDirectory with: python -m tests.test_project. When you run the script this way, either of the kinds of imports you tried will work.
But if myDirectory is supposed to be a top-level package itself (as the __init__.py file suggests), you should probably go up one level further up, to myDirectory's parent, and run the script with two levels of package names: python -m myDirectory.tests.test_project. If you do this and want the test to use an absolute import you'd need to name the top level package that the project module is in: from myDirectory.project import Project.
I'm upgrading a bunch of scripts where the ecosystem is a bit of a mess. The scripts always relied on external modules, and didn't have any package infrastructure of their own (they also didn't do much OOP, as you can imagine). There's nothing at the top level, but it is the working directory when starting Python and I'd like to keep it that way. At the top-level, I've just created __init__.py file (based on another question). As I'm less experienced with Python __init__.py confuses me a bit. All of the __init__.py files I've created are empty, it's my understanding that this is all that's required.
Assume I have the following directory structure:
__init__.py
dev.properties
prod.properties
F/
Foo.py
__init__.py
B/
bar.py
__init__.py
And the code is like this :
# Foo.py
from ..b import bar
barFunc()
# bar.py
def barFunc():
print "Hello, World!"
sys.stdout.flush()
I've created __init__.py at the root, in F/ and in B/. However, when I run python F/Foo.py, I get an error:
Traceback (most recent call last):
File "F/Foo.py", line 3, in <module>
from ..b import bar
ValueError: Attempted relative import in non-package
What exactly would I need to do to invoke python F/Foo.py and be able to depend on things defined in sibling directories?
Update
Thanks to #user2455127, I realized that I forgot to remove the file extension .py and my working directory was wrong. From the mypackage directory, running python -m mypackage/F/Foo, the error was : myvirtualenv/bin/python: No module named mypackage/B/bar.
Re-reading #user2455127's post, I ran from the directory above and get a long Traceback:
Traceback (most recent call last):
File "/usr/lib/python2.7/runpy.py", line 162, in _run_module_as_main
"__main__", fname, loader, pkg_name)
File "/usr/lib/python2.7/runpy.py", line 72, in _run_code
exec code in run_globals
File "<full path>/mypackage/foo/Foo.py", line 24, in <module>
from ..b import bar
ValueError: Attempted relative import in non-package
I'm not quite sure what needs to be done to fix this, but it seems like the __package__ attribute may help. I'll try and figure that out, and post another update.
If the current working directory is F's and B's parent directory, then F and B are available as modules to all Python code. You should run:
$ F/foo.py
and then F/foo.py should contain
from B.bar import barFunc
barFunc()
As for __init__.py, that file's existance simply makes the directory an importable module. If you want to know more about it, check the docs on how imports work. (For most people, reading all of that isn't necessary.)
Relative imports can be pretty messy, so I'd advise shying away from them for now.
Have a look to this :
Attempted relative import in non-package even with init.py and brenBarn's answer
If you run it from the folder upper than the one with dev.properties and the others files (called lambda in my case), with this command line :
python -m lambda.F.Foo
it works.