This doesn't seem to be an issue in python 3 but I'm needing to use python 2.7 for this and get the following issue
DIRECTORY STRUCTURE
module
├── __init__.py
└── submodule
├── __init__.py
└── test.py
# module/__init__.py
from module import submodule
# module/submodule/__init__.py
from module.submodule import test
# module/submodule/test.py
from module import submodule
when I try to import module from somewhere else it results in the following error:
>>> import module
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "module/__init__.py", line 1, in <module>
from module import submodule
File "module/submodule/__init__.py", line 1, in <module>
from module.submodule import test
File "module/submodule/test.py", line 1, in <module>
from module import submodule
ImportError: cannot import name submodule
I'm assuming the issue has something to do with circular imports but i need to use submodule in both module/__init__.py and module/submodule/test.py
any help is appreciated
As you've mentioned circular imports, one way to resolve this is by importing the module locally.
For e.g.
def fun():
from module import submodule
Related
I've got a project with the following structure:
\main_model
__init__.py
main.py
\second_module
__init__.py
second.py
\third_module
__init__.py
third.py
second_module and third_module are both Git submodules used as libraries by many other projects.
The first line of main.py is an import statement: from main_model.second_module import second
And the first line of second.py is too: from second_module.third_module import third
Running main.py raises an error with the following Traceback:
Traceback (most recent call last):
File "/main_model/main.py", line 1, in <module>
from main_model.second_module import func_a, func_b
File "/main_model/second_module/second.py", line 1, in <module>
from third_module.third import func_c, func_d
ModuleNotFoundError: No module named 'third_module'
So evidently I would need to amend the import statement in second.py to be from main_model.second_module.third_module import third. I can't do that, though, because second_module is a standalone submodule.
Is there a consistent way of structuring the imports, or modifying PYTHONPATH, that would allow the same import syntax from all levels?
I have a file hierarchy of a python package, "try_from_import", like this:
.
├── __init__.py
├── fibo.py
└── test
└── __init__.py
Within the directory "test", I cannot import the module fibo.py:
In [1]: from .. import fibo
---------------------------------------------------------------------------
ImportError Traceback (most recent call last)
<ipython-input-1-94aab0998156> in <module>
----> 1 from .. import fibo
ImportError: attempted relative import with no known parent package
How can I import the module fibo from the folder "test"? I am using python 3.7 on a Mac OS if that matters.
[update] Following the advice in the comments, "do not run python from within the package", I tried to run a file test/test.py which contains "from .. import fibo" from outside the package named "try_from_import". But I still got the error:
% python try_from_import/test/test.py
Traceback (most recent call last):
File "try_from_import/test/test.py", line 1, in <module>
from .. import fibo
(Solved)
This link https://dev.to/codemouse92/dead-simple-python-project-structure-and-imports-38c6 explains Python structure and imports well, too.
I have created a Python package test_pkg.
test_pkg/
├── setup.py
└── test_pkg
├── __init__.py
├── main.py
└── sub_pkg
├── __init__.py
└── sub_pkg_a.py
In the main.py, a module from a sub-package will be imported,
but I have to explicitly write:
from test_pkg.sub_pkg import sub_pkg_a
Otherwise, if I only write:
from sub_pkg import sub_pkg_a
Python will report:
>>> import test_pkg.main
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/home/zheng/tests/test_pkg/test_pkg/main.py", line 2, in <module>
from sub_pkg import sub_pkg_a
ModuleNotFoundError: No module named 'sub_pkg'
Could you tell me why the package name is required: test_pkg.sub_pkg?
The relative import works fine with the package, but if I execute the main.py script directly, there will be another import error:
~/tests/test_pkg/test_pkg$ python3 main.py
Traceback (most recent call last):
File "main.py", line 2, in <module>
from .sub_pkg import sub_pkg_a
ModuleNotFoundError: No module named '__main__.sub_pkg'; '__main__' is not a package
So, the question is: paths of __init__.sub_pkg and __main__.sub_pkg are different?
What you need to use here is relative import.
Try running the same thing with
from .sub_pkg import sub_pkg_a
The dot in this case refers to "relative to the file that import is in", in this case relative to the location of main.py
This article explains it pretty nicely https://realpython.com/absolute-vs-relative-python-imports/
I have a folder structure like this:
api
-- test
-- test_api.py
-- __init__.py
-- api
-- api.py
-- __init__.py
-- sub
-- sub.py
-- __init__.py
sub.py:
Base = 'base'
api.py:
from sub.sub import Base
def stuff_to_test():
pass
test_api.py:
from api.api import stuff_to_test
def test_stuff_to_test():
stuff_to_test()
I am in directory api.
I run pytest:
==================================== ERRORS ====================================
______________________ ERROR collecting tests/test_api.py ______________________
ImportError while importing test module '/<somepath>/api/tests/test_api.py'.
Hint: make sure your test modules/packages have valid Python names.
Traceback:
tests/test_api.py:1: in <module>
from ..api.api import stuff_to_test
api/__init__.py:1: in <module>
from . import api
api/api.py:1: in <module>
from sub.sub import Base
E ImportError: No module named 'sub'
!!!!!!!!!!!!!!!!!!! Interrupted: 1 errors during collection !!!!!!!!!!!!!!!!!!!!
=========================== 1 error in 0.08 seconds ============================
Same happens if I run the python interpreter and import stuff from test_api.py:
>>> from tests.test_api import *
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/<somepath>/api/tests/test_api.py", line 1, in <module>
from api.api import stuff_to_test
File "/<somepath>/api/api/__init__.py", line 1, in <module>
from . import api
File "/<somepath>/api/api/api.py", line 1, in <module>
from sub.sub import Base
ImportError: No module named 'sub'
My first idea was to make the import in api.py relative:
from .sub.sub import Base
This way tests run fine.
But if I run python api/api.py I get this error:
Traceback (most recent call last):
File "api/api.py", line 1, in <module>
from .sub.sub import Base
SystemError: Parent module '' not loaded, cannot perform relative import
How can I have it so tests run and application runs?
I solved it by adding the following to test.__init__.py
project_path = os.path.dirname(os.path.dirname(os.path.realpath(__file__)))
api_path= os.path.join(project_path, 'api')
sys.path.append(api_path)
In python there are two ways to import a module, with a relative path or with an absolute path.
When you write from sub.sub import Base you are doing an absolute path import, for a relative path import write from .sub.sub import Base.
An absolute path import go look in the PYTHONPATH to find the starting point of your import, so you should write from api.sub.sub import Base.
For more information: Absolute vs. explicit relative import of Python module
I want to run my python program from command line but it gives me below error
ImportError: No module named 'main'
My folder structure is as below
Project
|-----main
|-----__init__.py
|-----S3Operations.py
|-----BusinessOperations.py
My init.py code is as below
import sys
from S3Operations import Models
sys.path.append("D:/code/Project/main")
if __name__ == '__main__':
s3=Models()
s3.test()
And my S3Operations.py code is
import os.path
from main import BusinessService
class ModelsMlS3(object):
def test(self):
print("Testing success")
When I run the program using command line i get the below error
$ python __init__.py
Traceback (most recent call last):
File "__init__.py", line 2, in <module>
from S3Operations import ModelsMlS3
File "D:\code\Project\main\S3Operations.py", line 11, in <module>
from main import BusinessService
ImportError: No module named 'main'
Can any one please suggest a solution for the same.
You just need to do:
import BusinessService # instead of `from main import BusinessService`
as in your project, there is no __init__.py file present in Project directory (which holds main.py).
For importing it like:
from main import BusinessService
you need to create __init__.py in the folder in order to make it as module.