遍历给定目录中的python文件并导入它们？

Question

I'm working on a little pet project in python, and I want to be able to write external modules and dynamically import them. So far, I've got something like this:

def getModules(self):
    os.chdir(moduleDir)
    for module in os.listdir():
          #code goes here to import
          #also append to a list for use later on

I'd use import module , but that just gives a Syntax Error.

Answer 1

You can use importlib.import_module() like this:

import importlib

my_modules = []

def getModules(self):
    os.chdir(moduleDir)
    for module in os.listdir():
          my_module = importlib.import_module(module[:-3])  # Or: module.split('.')[0]
          my_modules.append(my_module)

Example:

Let's say we have a module a that contains the following function:

def fn():
    print("Hello World")

The following is the result:

>>> import importlib
>>>
>>> my_module = importlib.import_module('a')  # Note: 'a' without '.py'
>>>
>>> my_module.fn()
Hello World

Answer 2

You should use the __import__ function. Something like this will help,

def getModules(self):
    modules = []
    os.chdir(moduleDir)
    for module in os.listdir('.'):
          m = __import__(module.split('.')[0]) # Assuming your listdir() gives .py files
          modules.append(m)

A still better choice would be importlib.import_module() which is a wrapper around __import__ . It's got a similar syntax to __import__ . Of course, you need to import importlib .