This is the first time I've really sat down and tried python 3, and seem to be failing miserably. I have the following two files:
config.py has a few functions defined in it as well as a few variables. I've stripped it down to the following:
config.py
debug = True
test.py
import config
print (config.debug)
I also have an __init__.py
However, I'm getting the following error:
ModuleNotFoundError: No module named 'config'
I'm aware that the py3 convention is to use absolute imports:
from . import config
However, this leads to the following error:
ImportError: cannot import name 'config'
So I'm at a loss as to what to do here... Any help is greatly appreciated. :)
This question is related to
python
python-3.x
package
python-import
relative-import
This example works on Python 3.6.
I suggest going to Run -> Edit Configurations
in PyCharm, deleting any entries there, and trying to run the code through PyCharm again.
If that doesn't work, check your project interpreter (Settings -> Project Interpreter) and run configuration defaults (Run -> Edit Configurations...).
Set PYTHONPATH
environment variable in root project directory.
Considering UNIX-like:
export PYTHONPATH=.
TL;DR: You can't do relative imports from the file you execute since __main__
module is not a part of a package.
Absolute imports - import something available on sys.path
Relative imports - import something relative to the current module, must be a part of a package
If you're running both variants in exactly the same way, one of them should work. Here is an example that should help you understand what's going on. Let's add another main.py
file with the overall directory structure like this:
.
./main.py
./ryan/__init__.py
./ryan/config.py
./ryan/test.py
And let's update test.py
to see what's going on:
# config.py
debug = True
# test.py
print(__name__)
try:
# Trying to find module in the parent package
from . import config
print(config.debug)
del config
except ImportError:
print('Relative import failed')
try:
# Trying to find module on sys.path
import config
print(config.debug)
except ModuleNotFoundError:
print('Absolute import failed')
# main.py
import ryan.test
Let's run test.py
first:
$ python ryan/test.py
__main__
Relative import failed
True
Here "test" is the __main__
module and doesn't know anything about belonging to a package. However import config
should work, since the ryan
folder will be added to sys.path
.
Let's run main.py
instead:
$ python main.py
ryan.test
True
Absolute import failed
And here test is inside of the "ryan" package and can perform relative imports. import config
fails since implicit relative imports are not allowed in Python 3.
Hope this helped.
P.S.: If you're sticking with Python 3 there is no more need for __init__.py
files.
I figured it out. Very frustrating, especially coming from python2.
You have to add a .
to the module, regardless of whether or not it is relative or absolute.
I created the directory setup as follows.
/main.py
--/lib
--/__init__.py
--/mody.py
--/modx.py
modx.py
def does_something():
return "I gave you this string."
mody.py
from modx import does_something
def loaded():
string = does_something()
print(string)
main.py
from lib import mody
mody.loaded()
when I execute main, this is what happens
$ python main.py
Traceback (most recent call last):
File "main.py", line 2, in <module>
from lib import mody
File "/mnt/c/Users/Austin/Dropbox/Source/Python/virtualenviron/mock/package/lib/mody.py", line 1, in <module>
from modx import does_something
ImportError: No module named 'modx'
I ran 2to3, and the core output was this
RefactoringTool: Refactored lib/mody.py
--- lib/mody.py (original)
+++ lib/mody.py (refactored)
@@ -1,4 +1,4 @@
-from modx import does_something
+from .modx import does_something
def loaded():
string = does_something()
RefactoringTool: Files that need to be modified:
RefactoringTool: lib/modx.py
RefactoringTool: lib/mody.py
I had to modify mody.py's import statement to fix it
try:
from modx import does_something
except ImportError:
from .modx import does_something
def loaded():
string = does_something()
print(string)
Then I ran main.py again and got the expected output
$ python main.py
I gave you this string.
Lastly, just to clean it up and make it portable between 2 and 3.
from __future__ import absolute_import
from .modx import does_something
Try
from . import config
What that does is import from the same folder level. If you directly try to import it assumes it's a subordinate
Declare correct sys.path list before you call module:
import os, sys
#'/home/user/example/parent/child'
current_path = os.path.abspath('.')
#'/home/user/example/parent'
parent_path = os.path.dirname(current_path)
sys.path.append(parent_path)
os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'child.settings')
You can simply add following file to your tests directory, and then python will run it before the tests
__init__.py file
import os
import sys
sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), '..')))
Tried your example
from . import config
got the following SystemError:
/usr/bin/python3.4 test.py
Traceback (most recent call last):
File "test.py", line 1, in
from . import config
SystemError: Parent module '' not loaded, cannot perform relative import
This will work for me:
import config
print('debug=%s'%config.debug)
>>>debug=True
Tested with Python:3.4.2 - PyCharm 2016.3.2
Beside this PyCharm offers you to Import this name.
You hav to click on config
and a help icon appears.
For me, simply adding the current directory worked.
Using the following structure:
+-- myproject
+-- a.py
+-- b.py
a.py:
from b import some_object
# returns ModuleNotFound error
from myproject.b import some_object
# works
Setting PYTHONPATH can also help with this problem.
Here is how it can be done on Windows
set PYTHONPATH=.
If you are using python 3+ then try adding below lines
import os, sys
dir_path = os.path.dirname(os.path.realpath(__file__))
parent_dir_path = os.path.abspath(os.path.join(dir_path, os.pardir))
sys.path.insert(0, parent_dir_path)
You have to append your project's path to PYTHONPATH
and make sure to use absolute imports.
For UNIX (Linux, OSX, ...)
export PYTHONPATH="${PYTHONPATH}:/path/to/your/project/"
For Windows
set PYTHONPATH=%PYTHONPATH%;C:\path\to\your\project\
Absolute imports
Assuming that we have the following project structure,
+-- myproject
+-- mypackage
¦ +-- a.py
+-- anotherpackage
+-- b.py
+-- c.py
+-- mysubpackage
+-- d.py
just make sure to reference each import starting from the project's root directory. For instance,
# in module a.py
import anotherpackage.mysubpackage.d
# in module b
import anotherpackage.c
import mypackage.a
For a more comprehensive explanation, refer to the article How to fix ModuleNotFoundError and ImportError
Source: Stackoverflow.com