如何更改 Python 模块名称？

Question

Is it only possible if I rename the file? Or is there a __module__ variable to the file to define what's its name?

Answer 1

If you really want to import the file 'oldname.py' with the statement 'import newname', there is a trick that makes it possible: Import the module somewhere with the old name, then inject it into sys.modules with the new name. Subsequent import statements will also find it under the new name. Code sample:

# this is in file 'oldname.py'
...module code...

Usage:

# inject the 'oldname' module with a new name
import oldname
import sys
sys.modules['newname'] = oldname

Now you can everywhere your module with import newname .

Answer 2

You can change the name used for a module when importing by using as:

import foo as bar
print bar.baz

Answer 3

Yes, you should rename the file. Best would be after you have done that to remove the oldname.pyc and oldname.pyo compiled files (if present) from your system, otherwise the module will be importable under the old name too.

Answer 4

When you do import module_name the Python interpreter looks for a file module_name .extension in PYTHONPATH. So there's no chaging that name without changing name of the file. But of course you can do:

import module_name as new_module_name

or even

import module_name.submodule.subsubmodule as short_name

Useful eg. for writing DB code.

import sqlite3 as sql
sql.whatever..

And then to switch eg. sqlite3 to pysqlite you just change the import line

Answer 5

I had an issue like this with bsddb. I was forced to install the bsddb3 module but hundreds of scripts imported bsddb. Instead of changing the import in all of them, I extracted the bsddb3 egg, and created a soft link in the site-packages directory so that both "bsddb" and "bsddb3" were one in the same to python.

Answer 6

Every class has an __module__ property, although I believe changing this will not change the namespace of the Class.

If it is possible, it would probably involve using setattr to insert the methods or class into the desired module, although you run the risk of making your code very confusing to your future peers.

Your best bet is to rename the file.

Answer 7

Where would you like to have this __module__ variable, so your original script knows what to import? Modules are recognized by file names and looked in paths defined in sys.path variable.

So, you have to rename the file, then remove the oldname.pyc , just to make sure everything works right.

Answer 8

You can set the module via module attribute like below.

func.__module__ = module

You can even create a decorator to change the module names for specific functions in a file for example:

def set_module(module):
    """Decorator for overriding __module__ on a function or class.
    Example usage::
        @set_module('numpy')
        def example():
            pass
        assert example.__module__ == 'numpy'
    """
    def decorator(func):
        if module is not None:
            func.__module__ = module
        return func
    return 

and then use

@set_module('my_module')
def some_func(...):

Pay attention since this decorator is for changing individual module names for functions.

This example is taken from numpy source code: https://github.com/numpy/numpy/blob/0721406ede8b983b8689d8b70556499fc2aea28a/numpy/core/numeric.py#L289