I know how to import a package or module, but I meet a quite strange problem.
If I run swmm5_extend_function/example.py, everything is fine. However, when I run example.py, errors occur:
Traceback (most recent call last):
File "example.py", line 2, in <module>
from swmm5_extend_function.Swmm5Extend import SWMM5ReadInp
File "C:\project\swmm5_extend_function\Swmm5Extend.py", line 1, in <module>
import swig.SWMM5ReadInpFile as swmm
ModuleNotFoundError: No module named 'swig'
Here is my project structure:
project/
-- example.py
-- ......
-- swmm5_extend_function/
-- __init__.py
-- example.py
-- Swmm5Extend.py
-- swig/
-- __init__.py
-- SWMM5ReadInpFile.py
-- ....
Here is code of each .py file:
swmm5_extend_function/Swmm5Extend.py
import swig.SWMM5ReadInpFile as swmm
class SWMM5ReadInp(object):
pass
swmm5_extend_function/example.py
from Swmm5Extend import SWMM5ReadInp
example.py
from swmm5_extend_function.Swmm5Extend import SWMM5ReadInp
I want to know why this strange error happens.
For a better explanation, I've created the following folder structure:
test/
-- __init__.py
-- greeter.py # Greets in German
-- subfolder/
-- __init__.py
-- greeter.py # Greets in Italian
-- test.py
-- deepfolder/
-- __init__.py
-- greeter.py # Greets in France
As you may notice, we have 3 files with the same name, each one greets in a different language using a function with the same name. The only function in a greeter.py file is:
def says():
print("Hello World!")
IMPORT FROM THE SAME FOLDER
If from test.py file we import greeter and run the says function, we'll have:
import greeter as greeter
greeter.says()
Output:
Buongiorno Mondo! # Italian output
IMPORT FROM A SUBFOLDER
But what if we want to import from a subfolder?
To import from a subfolder (i.e., deepfolder/), we simply add an empty __init__.py file into the folder, then we can specify the path in the import:
import deepfolder.greeter as greeter
greeter.says()
Output:
Bonjour le Monde! # France output
IMPORT FROM A PARENT FOLDER
At last, you may want to import from a parent folder.
You should try to have your main running file at the top of the folder tree, but things happens and you find yourself looking to import a module from a parent folder.
For doing this, you need to add the parent folder to the sys.path:
import sys
sys.path.append("/path/to/dir")
from test import greeter as greeter
greeter.says()
Output:
Guten Morgen Welt! # German output
Importing scripts and modules isn't really the most pythonic way to solve things, you may want to have a look on Python's documentation about packages.
TL;DR
In your project/example.py use
import swmm5_extend_function.swig.SWMM5ReadInpFile as swmm
instead of
import swig.SWMM5ReadInpFile as swmm
Related
I have a Python project in which I have the following folder structure:
> root
> download_module
> __init__.py
> downloadProcess.py
> sharedFunctions.py
> someHelper.py
> useSharedFunction.py
The download_module/__init__.py has the following code:
from .sharedFunctions import stringArgumentToDate
from .downloadProcess import downloadProcessMethod
The sharedFunctions.py file contains the following function:
def stringArgumentToDate(arg):
dateformat = "%m/%d/%Y"
date = None
if arg.isnumeric():
date = datetime.fromtimestamp(int(arg))
if date == None:
date = datetime.strptime(arg, dateformat)
return date
Then on the useSharedFunction.py I try to import the shared function and use it like this.
from download_module import stringArgumentToDate
from download_module import downloadProcessMethod
def main():
arg = '03/14/2022'
dateArg = stringArgumentToDate(arg)
if __name__ == '__main__':
main()
When I try to run this by using python3 useSharedFunction.py I got the following error:
Traceback (most recent call last):
File "useSharedFunction.py", line 4, in <module>
from download_module import stringArgumentToDate
File "/Users/jacobo/Documents/project/download_module/__init__.py", line 2, in <module>
from .download_module import downloadAndProcessMethod
File "/Users/jacobo/Documents/project/download_module/downloadProcess.py", line 10, in <module>
from sharedFunctions import stringArgumentToDate, otherFunction
ModuleNotFoundError: No module named 'sharedFunctions'
I do believe the error is in downloadProcess since at the beggining of the file we got this import:
from sharedFunctions import stringArgumentToDate, otherFunction
from someHelper import Helper
Which refers to sibling files.
However I'm unsure what will be a proper fix to allow to run the downloadProcess.py main independently but also, being able to call it one of its method from a root or any other file out of the module.
Consider this structure:
┬ module
| ├ __init__.py
| ├ importing_submodule.py
| └ some_submodule.py
├ __main__.py
├ some_submodule.py
└ module_in_parent_dir.py
with content:
__main__.py
import module
/module/__init__.py
from . import importing_submodule
/module/importing_submodule.py
from some_submodule import SomeClass
/module/some_submodule.py
print("you imported from module")
class SomeClass:
pass
/some_submodule.py
print("you imported from root")
class SomeClass:
pass
/module_in_parent_dir.py
class SomeOtherClass:
pass
How sibling import works
(skip this section if you know already)
Now lets run __main__.py and it will say "you imported from root".
But if we change code a bit..
/module/importing_submodule.py
from module.some_submodule import SomeClass
It now says "You imported from module" as we wanted, probably with scary red line in IDE saying "Unresolved reference" if you didn't config working directory in IDE.
How this happen is simple: script root(Current working directory) is decided by main script(first script that's running), and python uses namespaces.
Python's import system uses 2 import method, and for convenience let's call it absolute import and relative import.
Absolute import: Import from dir listed in sys.path and current working directory
Relative import: Import relative to the very script that called import
And what decide the behavior is whether we use . at start of module name or not.
Since we imported by from some_submodule without preceeding dot, python take it as 'Absolute import'(the term we decided earlier).
And then when we also specified module name like from module.some_submodule python looks for module in path list or in current working directory.
Of course, this is never a good idea; script root can change via calls like os.chdir() then submodules inside module folder may get lost.
Therefore, the best practices for sibling import is using relative import inside module folder.
/module/importing_submodule.py
from .some_submodule import SomeClass
Making script that work in both way
To make submodule import it's siblings when running as main script, yet still work as submodule when imported by other script, then use try - except and look for ImportError.
For importing_submodule.py as an example:
/module/importing_submodule.py
try:
from .some_submodule import SomeClass
except ImportError:
# attempted relative import with no known parent package
# because this is running as main script, there's no parent package.
from some_submodule import SomeClass
Importing modules from parent directory is a bit more tricky.
Since submodule is now main script, relative import to parent level directory doesn't work.
So we need to add the parent directory to sys.path, when the script is running as main script.
/module/importing_submodule.py
try:
from .some_submodule import SomeClass
except ImportError:
# attempted relative import with no known parent package
# because this is running as main script, there's no parent package.
from some_submodule import SomeClass
# now since we don't have parent package, we just append the path.
from sys import path
import pathlib
path.append(pathlib.Path(__file__).parent.parent.as_posix())
print("Importing module_in_parent_dir from sys.path")
else:
print("Importing module_in_parent_dir from working directory")
# Now either case we have parent directory of `module_in_parent_dir`
# in working dir or path, we can import it
# might need to suppress false IDE warning this case.
# noinspection PyUnresolvedReferences
from module_in_parent_dir import SomeOtherClass
Output:
"C:\Program Files\Python310\python.exe" .../module/importing_module.py
you imported from module
Importing module_in_parent_dir from sys.path
Process finished with exit code 0
"C:\Program Files\Python310\python.exe" .../__main__.py
you imported from module
Importing module_in_parent_dir from working directory
Process finished with exit code 0
when i use http://github.com/joshthecoder/tweepy-examples ,
i find :
import tweepy
in the appengine\oauth_example\handlers.py
but i can't find a tweepy file or tweepy's 'py' file, except a tweepy.zip file,
i don't think this is right,cauz i never import a zip file,
i find this in app.py:
import sys
sys.path.insert(0, 'tweepy.zip')
why ?
how to import a zip file..
thanks
updated
a.py :
import sys
sys.path.insert(0, 'b.zip')
import b
print b
b.zip:
b file
|-----__init__.py
|-----c.py
c.py:
cc='ccccc'
the error is :
> "D:\Python25\pythonw.exe" "D:\zjm_code\a.py"
Traceback (most recent call last):
File "D:\zjm_code\a.py", line 9, in <module>
import b
ImportError: No module named b
updated2
it is ok now ,
the error's reason is : i rename b.rar to b.zip
The name of the zip file is irrelevent when searching for modules - this allows you to include version numbers in the file name, such as my_b_package.1.2.3.zip.
To import from a zip file, you need to replicate the full package structure within it. In this case, you need a package b, with the __init__.py and c.py modules.
I.e:
b.zip
|
| -- b <dir>
| -- __init__.py
| -- c.py
You don't import zip files, you add them to sys.path so that you can import modules within them. sys.path is a list, and as such the normal list methods/operations (e.g. .append()) all work on it.
i want to make a sample package in python 2.7 just to clear my concepts whose structure looks like this:
calculator/
main.py
operations/
file1.py
file2.py
__init__.py
new_operations/
__init__.py
file3.py
main.py content: (this file is present inside calculator folder)
from operations import power
print power(2,2)
__init__.py content: (this file is present inside operations folder)
from .file1 import add
from .file1 import sub
from .file2 import mul
from .file2 import div
file1.py content: (this file is present inside operations folder)
def add(a,b):
return(a+b)
def sub(a,b):
return(a-b)
file2.py content: (this file is present inside operations folder)
def mul(a,b):
return(a*b)
def div(a,b):
return(a/b)
__init__.py content: (this file is present inside new_operations folder)
from .file3 import power
file3.py content: (this file is present inside new_operations folder)
def power(a,b):
return(a**b)
Now, when i run main.py, i got following error:
Traceback (most recent call last):
File "C:\Python27\mycodes\calculator\main.py", line 3, in <module>
from operations import power
ImportError: cannot import name power
Can anyone tell me, what mistake i am doing ? Help me.
Use the following line in your "main.py" file:
from operations.new_operations import power
You are missing an 'add' function in your calculator module. If you create an 'add' function, I would assume that the code would work.
maybe try doing this in the module calculator:
def add(num1,num2):
print(num1+num2)
return num1+num2;
If you don't want it to print while calculating, remove the print statement.
Hope this helps!
It's my first post here, please understand that I'm a beginner and that I'm learning "on-the-job".
Can someone explain how can I import files from a different module in a Maya python script? I'm getting the following error:
Error: ImportError: file E:/.../bin/mainScript.py line 17: No module named tools
Here are my directories and codes:
Main_folder\
|-- install.mel
|-- ReadMeFirst.txt
`-- bin\
|-- __init__.py
|-- mainScript.py
|-- tools.py
`-- presets\
|-- bipedPreset.txt
|-- quadrupedPreset.txt
`-- [...] .txt
I'm trying to import tools.py in mainScript.py
EDIT:
Ok, as it won't fit in a comment I edit this post to add precisions. I moved the 'Main_folder' on my Desktop and ran the script once again in Maya. It still doesn't work but I have a more complete error traceback. Here it is:
# Error: Error in maya.utils._guiExceptHook:
# File "C:\Program Files\Autodesk\Maya2014\Python\lib\site-packages\maya\utils.py", line 332, in formatGuiException
# result = u'%s: file %s line %s: %s' % (exceptionType.__name__, file, line, exceptionMsg)
# UnicodeDecodeError: 'ascii' codec can't decode byte 0xfc in position 11: ordinal not in range(128)
#
# Original exception was:
# Traceback (most recent call last):
# File "<maya console>", line 3, in <module>
# File "C:/Users/UKDP/Desktop/Main_folder/bin/mainScript.py", line 17, in <module>
# from tools import ClassTest
# ImportError: No module named tools #
You need to make sure any importable modules are on you python path.
If your files are in E:/main_folder you'll need to do
import sys
sys.path.append("E:/main_folder")
import bin.tools
import bin.mainScript
and so on. The way you have it set up (with 'bin/__init__.py') you're telling python that the module is named bin and it has submodules named 'mainScript' and 'tools'. Long discussion here
Try importing like:
>>>import san.libs.stringops
Where the san is dir(in san create __init__.py)
libs is a dir(in libs create __init__.py)
and stringops.py is imported
Try this
I have a folder that is on my desktop and the folder is called Combo and has a script called combo.py and here is how I access it:
import sys #imports system's directory module
sys.path.insert(0,"C:/Users/dharmin.doshi/Desktop") #Add your directory, do not add your folder in the path unless the script is inside of folder inside of folder. Path needs to be in quotes and 0 is added as needed by the argument.
from Combo(Folder name) import combo (my python script)
reload (combo) #Optional to reload it every time you make changes to the script.
combo.run() #Call the function that runs the code.
In your case if you need to access tools.py then your path will be like:
sys.path.insert(0, "MainFolder/bin")
import tools
Hope this helps :)
exe1.py
import san.libs.stringops
import san.libs.maths
import san.libs.utils.ran
import san.printing
newstr = san.libs.stringops.add2string("hey","hi")
san.printing.myprint(newstr)
result = san.libs.maths.add(2,3)
san.printing.myprint(result)
random_number = san.libs.utils.ran.getnumber()
san.printing.myprint(random_number)
my dir location,i am in a.py:
my_Project
|----blog
|-----__init__.py
|-----a.py
|-----blog.py
when i 'from blog import something' in a.py , it show error:
from blog import BaseRequestHandler
ImportError: cannot import name BaseRequestHandler
i think it import the blog folder,not the blog.py
so how to import the blog.py
updated
when i use 'blog.blog', it show this:
from blog.blog import BaseRequestHandler
ImportError: No module named blog
updated2
my sys.path is :
['D:\\zjm_code', 'D:\\Python25\\lib\\site-packages\\setuptools-0.6c11-py2.5.egg', 'D:\\Python25\\lib\\site-packages\\whoosh-0.3.18-py2.5.egg', 'C:\\WINDOWS\\system32\\python25.zip', 'D:\\Python25\\DLLs', 'D:\\Python25\\lib', 'D:\\Python25\\lib\\plat-win', 'D:\\Python25\\lib\\lib-tk', 'D:\\Python25', 'D:\\Python25\\lib\\site-packages', 'D:\\Python25\\lib\\site-packages\\PIL']
zjm_code
|-----a.py
|-----b.py
a.py is :
c="ccc"
b.py is :
from a import c
print c
and when i execute b.py ,i show this:
> "D:\Python25\pythonw.exe" "D:\zjm_code\b.py"
Traceback (most recent call last):
File "D:\zjm_code\b.py", line 2, in <module>
from a import c
ImportError: cannot import name c
When you are in a.py, import blog should import the local blog.py and nothing else. Quoting the docs:
modules are searched in the list of directories given by the variable sys.path which is initialized from the directory containing the input script
So my guess is that somehow, the name BaseRequestHandler is not defined in the file blog.py.
what happens when you:
import blog
Try outputting your sys.path, in order to make sure that you have the right dir to call the module from.