Python导入：导入没有.py扩展名的模块？

Question

In a Python system for which I develop, we usually have this module structure.

mymodule/
mymodule/mymodule/feature.py
mymodule/test/feature.py

This allows our little testing framework to easily import test/feature.py and run unit tests. However, we now have the need for some shell scripts (which are written in Python):

mymodule/
mymodule/scripts/yetanotherfeature.py
mymodule/test/yetanotherfeature.py

yetanotherfeature.py is installed by the module Debian package into /usr/bin. But we obviously don't want the .py extension there. So, in order for the test framework to still be able to import the module I have to do this symbolic link thingie:

mymodule/
mymodule/scripts/yetanotherfeature
mymodule/scripts/yetanotherfeature.py @ -> mymodule/scripts/yetanotherfeature
mymodule/test/yetanotherfeature.py

Is it possible to import a module by filename in Python, or can you think of a more elegant solution for this?

Answer 1

The imp module is used for this:

daniel@purplehaze:/tmp/test$ cat mymodule
print "woho!"
daniel@purplehaze:/tmp/test$ cat test.py 
import imp
imp.load_source("apanapansson", "mymodule")
daniel@purplehaze:/tmp/test$ python test.py
woho!
daniel@purplehaze:/tmp/test$ 

Answer 2

Check out imp module:

http://docs.python.org/library/imp.html

This will allow you to load a module by filename. But I think your symbolic link is a more elegant solution.

Answer 3

You could most likely use some tricker by using import hooks , I wouldn't recommend it though. On the other hand I would also probably do it the other way around , have your .py scripts somewhere, and make '.py'less symbolic links to the .py files. So your library could be anywhere and you can run the test from within by importing it normall (since it has the py extension), and then /usr/bin/yetanotherfeature points to it, so you can run it without the py.

Edit: Nevermind this (at least the hooks part), the import imp solution looks very good to me :)

Answer 4

Another option would be to use setuptools:

"...there's no easy way to have a script's filename match local conventions on both Windows and POSIX platforms. For another, you often have to create a separate file just for the “main” script, when your actual “main” is a function in a module somewhere... setuptools fixes all of these problems by automatically generating scripts for you with the correct extension, and on Windows it will even create an .exe file..."

https://pythonhosted.org/setuptools/setuptools.html#automatic-script-creation