Import arbitrary python source file. (Python 3.3+)

问题

How can I import an arbitrary python source file (whose filename could contain any characters, and does not always ends with .py) in Python 3.3+?

I used imp.load_module as follows:

>>> import imp
>>> path = \'/tmp/a-b.txt\'
>>> with open(path, \'U\') as f:
...     mod = imp.load_module(\'a_b\', f, path, (\'.py\', \'U\', imp.PY_SOURCE))
...
>>> mod
<module \'a_b\' from \'/tmp/a-b.txt\'>

It still works in Python 3.3, but according to imp.load_module documentation, it is deprecated:

Deprecated since version 3.3: Unneeded as loaders should be used to load modules and find_module() is deprecated.

and imp module documentation recommends to use importlib:

Note New programs should use importlib rather than this module.

What is the proper way to load an arbitrary python source file in Python 3.3+ without using the deprecated imp.load_module function?

回答1:

Found a solution from importlib test code.

Using importlib.machinery.SourceFileLoader:

>>> import importlib.machinery
>>> loader = importlib.machinery.SourceFileLoader('a_b', '/tmp/a-b.txt')
>>> mod = loader.load_module()
>>> mod
<module 'a_b' from '/tmp/a-b.txt'>

NOTE: only works in Python 3.3+.

UPDATE Loader.load_module is deprecated since Python 3.4. Use Loader.exec_module instead:

>>> import types
>>> import importlib.machinery
>>> loader = importlib.machinery.SourceFileLoader('a_b', '/tmp/a-b.txt')
>>> mod = types.ModuleType(loader.name)
>>> loader.exec_module(mod)
>>> mod
<module 'a_b'>

---

>>> import importlib.machinery
>>> import importlib.util
>>> loader = importlib.machinery.SourceFileLoader('a_b', '/tmp/a-b.txt')
>>> spec = importlib.util.spec_from_loader(loader.name, loader)
>>> mod = importlib.util.module_from_spec(spec)
>>> loader.exec_module(mod)
>>> mod
<module 'a_b' from '/tmp/a-b.txt'>

回答2:

Shorter version of @falsetru 's solution:

>>> import importlib.util
>>> spec = importlib.util.spec_from_file_location('a_b', '/tmp/a-b.py')
>>> mod = importlib.util.module_from_spec(spec)
>>> spec.loader.exec_module(mod)
>>> mod
<module 'a_b' from '/tmp/a-b.txt'>

I tested it with Python 3.5 and 3.6.

According to the comments, it does not work with arbitrary file extensions.

回答3:

Similar to @falsetru but for Python 3.5+ and accounting for what the importlib doc states on using importlib.util.module_from_spec over types.ModuleType:

This function [importlib.util.module_from_spec] is preferred over using types.ModuleType to create a new module as spec is used to set as many import-controlled attributes on the module as possible.

We are able to import any file with importlib alone by modifying the importlib.machinery.SOURCE_SUFFIXES list.

import importlib

importlib.machinery.SOURCE_SUFFIXES.append('') # empty string to allow any file
spec = importlib.util.spec_from_file_location(module_name, file_path)
module = importlib.util.module_from_spec(spec)
spec.loader.exec_module(module)
# if desired: importlib.machinery.SOURCE_SUFFIXES.pop()

来源：https://stackoverflow.com/questions/19009932/import-arbitrary-python-source-file-python-3-3