Why does importing from a module from the current directory only work when within that directory? - import

Background
I have a Python project with this directory structure:
py/:
db/ __init__.py run.py
py/db:
handle.py __init__.py util.py
The files are simple enough that I'm not sure I need to post them; nevertheless:
py/run.py
from db.handle import Handle
py/db/handle.py:
import util
class Handle:
def __init__(self, x):
self.x = util.addtwo(x)
py/db/util.py:
def addtwo(x):
return x + 2
If I run handle.py from within the db subdirectory, it imports util without error. However, when I run run.py, handle.py fails with an import error. I can guess that handle.py is being run in the py directory (instead of py/db), and putting a call to os.getcwd() in handle.py confirms this. I can fix this problem using sys.path like so (in run.py):
import sys
sys.path.append("db")
from db.handle import Handle
Question
When importing, from a subdirectory, a module that contains imports to other local modules in that directory, why doesn't Python check the current directory of the module making the import statement? In my example, why doesn't Python check the db first when handle.py contains import statements? Is there a PEP that describes this or is it a behavior with an obvious rationale that I missed?
I thought it might be related to PEP 328:
all import statements be absolute by default (searching sys.path only) with special syntax (leading dots) for accessing package-relative imports.
but I'm not sure.

Your import is "absolute" and module names is looked for in the PYTHONPATH, and that typically includes the current directory.
If you want to import a module from the same folder that your module is in, you use a relative import:
from . import util
or
from .util import addtwo

Related

Pytest can't find files/modules

I have had a look at several different topics on this matter but can't work out how to apply it to my situation. I don't have an init.py in my test folder and I have tried to use conftest. I have a directory structure like this:
--app
--app.py
--src
--init.py
--module1.py
--module2.py
--module3.py
--configs
--config.json
--non-default-config.json
--tests
--test1.py
--conftest.py
where app.py imports module1, which then imports modules 2&3 (using import src.module2). I load up config.json in all the modules files (and app.py) using:
with open('configs/config.json') as f:
CFG = json.load(f)
This works when I run app.py from the app directory. However, when I run pytest (which I believe should also be referencing from the app directory, since conftest.py is in the app directory) and it imports module1 (using import src.module1), it cannot find configs/config.json, but will find app/configs/config.json. I cannot use this as it will cause my app to break when I run app.py. However, Pytest can find the imports from within the src folder, even though this is on the same level as the configs folder.
If I move the conftest.py outside of the app directory and import module1 using import app.src.module1 then this import succeeds, but the import of module2 inside module1 then fails.
How can I resolve this issue? And is there a better way of structuring my project?
Solved this by running pytest from inside the app folder instead of from the base directory.

Python importing from incorrect module (which bears the same name), VSC

I have two modules, both named connection.py in two separate environments listed below. Both of the folders containing connection.py are in my PYTHONPATH system environment variable.
However, if that of spec is not placed above that of bvbot, spec's test_connection.py attempts to import from the connection.py of bvbot.
If in cmd, I can resolve this by moving the path of spec above that of bvbot. But, in Visual Studio Code, spec's test_connection.py still imports from bvbot's connection.py.
The two environments of interest are:
C:\Users\You_A\Desktop\2016Coding\VirtualEnviroments\spec\spec_trading
C:\Users\You_A\Desktop\2016Coding\VirtualEnviroments\bvbot\Legacy_bvbot
Structure of the spec path above:
src/
spec_trading/
__init__.py
connection.py
tests/
__init__.py
connection.py
spec test_connection.py:
import pytest
from connection import Connection, OandaConnection
class TestConnection:
def test_poll_timeout(self):
connection = Connection()
timeout = 10.0
connection.set_poll_timeout(timeout)
assert connection.poll_timeout == timeout
What I am doing wrong here? How can I resolve this without resorting to manually faffing with my systems environment variables and resolve the VSC issue?
Easiest solution is to not use implicit relative imports (I assume this is Python 2.7). Basically use explicit relative imports and make sure the imports resolve within the package they are contained within instead of Python having to search sys.path for the module.
And if you are using Python 2.7, put from __future__ import absolute_import at the top of the file.

How to import module up multiple levels from base?

I'm trying to call a module several levels up from pytest run directory. How do I import this module?
I've tried:
sys.path.insert(0, 'path/to/module')
import modulename
Here's the directory structure:
tools
common
modulename.py (contains class A)
functional_test (this is where I'm running pytest; tools/functional_test)
conftest.py
pytest.ini
tests
typea (this is tools/funtional_tests/tests/typea)
tests_typea1.py
Under tests_typea1.py, I want to import class A from modulename.py under tools/common.
Getting the following Errors:
ImportError
ModuleNotFoundError: No module named 'modulename'
Well, after having another person look over my code, I realized that I miss-spelled my the import . Ugh... Note to self: change font style and confirm spelling. :). The above sys.path.insert or sys.path.append with import <modulename> works.

ImportError: when importing from a local script library

Does importing from a local script lib work in qpython3?
I have a script I created in the Qpython projects3 directory of qpython.
projects3/MPU6502/
I have my main code here in this directory.
main.py
I have a local subdirectory,
projects3/MPU6502/tiny6502lib/
In this sub directory I have the source code,
RAM_8bit_Memory.py
From my main.py source code I load the library,
#-*-coding:utf8;-*-
#qpy:3
#qpy:console
# import 6502 library module
from tiny6502lib.RAM_8bit_Memory import *
when I execute the library import I get the ERRORL:
"ImportError: No module named tiny6502lib.RAM_8bit_Memory"
Is importing local script libraries broken in qpython3?
org.qpython.py/projects/MPU6502/main.py
org.qpython.py/projects/MPU6502/tiny6502lib/RAM_8bit_Memory.py
This code works perfectly on all other flavors of python3 (windows) and pythonista on ipad.
How do I get this import to work? Or does it not work at all?
thank you,
Just try to insert the following code before importing tiny6502lib.RAM_8bit_Memory
import sys
sys.path.append("/sdcard/qpython/projects3/MPU6502")
?

Python module function not defined

I am trying to import a module in my python script and I can't make it work.
So I have my python script: /home/user/pythonscript/oneDir/onescript.py
And I would like to use a script that is a directory higher in hierarchy:
/home/user/pythonscript/common.py
So I did the following at the top of my onescript.py:
import sys
sys.path.insert(1,'/home/user/pythonscript')
import common
In my common.py file, I have a function onecConnect, and when I try to run onescript.py, which uses onecConnect function, I get the following error: nameError: name 'onecConnect' is not defined
Anyone can see what I do wrong or forgot to do?
Thanks
Make sure there are __init__.py in all directories, go to /home/user/pythonscript and run Python code from there. So:
python oneDir/onescript.py
In onescript.py you can do:
from common import onecConnect
The rules are:
Always run a Python script from the highest possible directory (not the deepest into the project).
Always have full import lines, no relative imports.
This keeps the problems away.