I have following package stricture:
foo:
__init__.py
soft:
__init__.py
access.py
init.py has following line
from . import access
when I'm running the package foo.soft, it is giving an error:
ImportError: cannot import name access
But it works if I remove . and make the second init as following:
import access
But py3 requires the relative import to have ".". How to resolve this
py2 and py3 compatibility issue?
It has resolved by adding:
from __future__ import absolute_import
Related
The file structure for a module im creating goes as follows:
PIV
| __init__.py
| base.py
| core.py
| exceptions.py
.gitignore
LICENSE
requirements.txt
But whenever I run a file like core.py, I get the following error:
Traceback (most recent call last):
File "c:/Users/ghub4/OneDrive/Desktop/Python-Image-and-Video-tools/PIV/core.py", line 33, in <module>
from . import base
ImportError: attempted relative import with no known parent package
The same thing happens when I run the __init__.py file. I'm not sure on what went wrong because all of the python files are in the same folder. Can someone clarify what's the problem and explain how I should fix it?
Import code for core.py file:
from __future__ import absolute_import
import sys
import os
from PIL import Image
import io
from . import base
from . import exceptions
(The __init__.py folder has the same relative imports as in the core file but also including: from . import core)
Based upon the two links you will given below, here is what needed for the problem to solve:
Relative Imports error rectified
No module named base
You need to import the package as this
from mymodule import some_useful_method
Sometimes, we get the no module error, in this case, we can import like this
from module_name.classname import some_useful_method
Lets assume I have a module say utility.py
from __future__ import absolute_import
from __future__ import division
from __future__ import print_function
from datetime import datetime
import os
import random
import sys
import threading
import numpy as np
import tensorflow as tf
.....
I'd like to import this in my drive.py. I have it saved in my local directory and have in my first line
from . import utility
Is that possible, to issue a command in terminal to find the non-local modules ( tensorflow, numpy, etc), and install them using pip?
Any workaround would be appreciated.
CS
If you mean that you'd like the command to parse the file's imports and install missing dependancies automatically, then no it is not possible.
There are modules that are not imported with the pip's package name. For example the package facebook-sdk is imported as import facebook, making impossible to deduct the package name from the import.
Let's say there are two files - mask.py and main.py.
mask.py has some function that I'm importing into main.py.
So if that function in mask.py which I'm importing has dependency like "os", where should I import os - in mask.py or main.py.
Let us consider a scenario as you have stated by using two files mask.py and main.py.
mask.py
import os
def some_function():
os.environ['a_url'] = "something.com" # using dependency as you mentioned
main.py
from mask import some_function
# do something with the function
Now, coming to your query, if you use import os in main.py but not in mask.py, you will get NameError in mask.py saying:
NameError: name 'os' is not defined
This is because you need to import any dependency in the same file where it is used. Also, if both of your file uses this dependency, you need to import it in both the files.
Hope this clarifies your query.
I'm a bit new to the Python world. I'm using Python3 and having hard times with imports.
I was using PyCharm on Windows to write an application. Everything was working through the project until I switched to Linux and VS Code.
Now I can't use absolute imports for importing modules from other packages in the same project.
For example, I'd like to import from module cards all available card types.
I tested the classes and everything is ok. I'm only getting this issue with the import stuff.
The project structure:
/
|-cards
|-__init__.py
|-card.py
|-monster_card.py
|-spell_card.py
|-trap_card.py
|-ritual_card.py
|-deck
|-__init__py
|-deck.py
|-system
# This is the code in __init__.py in cads package
from . trap_card import TrapCard
from . spell_card import SpellCard
from . ritual_card import RitualCard
from . monster_card import MonsterCard
__all__ = [TrapCard, SpellCard, RitualCard, MonsterCard]
# The following line, for example, does not work from inside another package
# I'm trying to import the modules in cards from deck
from cards import TrapCard, MonsterCard, SpellCard, RitualCard
When I try to import packages from another folders I get this error message:
Traceback (most recent call last):
File "/root/git-repos/Yu-Gi-Oh/decks/deck.py", line 3, in
from cards import TrapCard, MonsterCard, SpellCard, RitualCard
ModuleNotFoundError: No module named 'cards'
When you call import *, python search the module from sys.path. You need to add your root dir into sys.path before call import stmt.
For your case, your root dir is /.
like:
import os
import sys
sys.path.append(os.path.dirname(os.path.dirname(__file__)))
from cards import *
other way
Add file __init__.py into your root dir for make it become a module. Then change from cards import * to from .cards import *.
If I execute demo2.py it works fine, the problem is when I execute main.py
|myPackage
|subPackage
demo.py
demo2.py
main.py
main.py
from ludikDriver.demo2 import demo2_print
demo2_print()
demo2.py
from demo import demoprint
def demo2_print():
print("demo2")
demoprint()
demo2_print()
demo.py
def demoprint():
print("demo")
Error:No module named 'demo'
Just use relative imports as suggested in pep 328.
from .demo import demoprint
You can do for the other package. Just as relative paths.
Your modules need context of themselves. You should have the "__init__.py" file in subPackage and myPackage. Then your import should be relative:
from . import demo
OR more in context of your example:
from .demo import demoprint
Your error is associated with the top line in demo.py:
from demo import demoprint
There is no module named demo