Another option is to use a binary environment variable, e.g. lets call it 'run_code'. If run_code = 0 (False) structure main.py to bypass the code (but the temporarily bypassed function will still be imported as a module). Later when you are ready to use the imported function (now a module) set the environment variable run_code = 1 (True). Use the os.environ command to set and retrieve the binary variable, but be sure to convert it to an integer when retrieving (or restructure the if statement to read a string value),

在main.py:

import os

#set environment variable to 0 (False):
os.environ['run_code'] = '0'


def binary_module():
    #retrieve environment variable, convert to integer
    run_code_val = int(os.environ['run_code'] )
    
    if run_code_val  == 0:
        print('nope. not doing it.')
    if run_code_val == 1:
        print('executing code...')
        # [do something]

.．.在任何加载main.py的脚本中:

import os,main

main.binary_module() 

输出:不。不做。

# now flip the on switch!
os.environ['run_code'] = '1'
main.binary_module()

输出:执行代码…

*注意:上面的代码假设main.py和任何导入它的脚本存在于同一个目录中。

A minor error that could happen (at least it happened to me), especially when distributing python scripts/functions that carry out a complete analysis, was to call the function directly at the end of the function .py file. The only things a user needed to modify were the input files and parameters. Doing so when you import you'll get the function running immediately. For proper behavior, you simply need to remove the inside call to the function and reserve it for the real calling file/function/portion of code

我做了一个简单的测试:

# test.py

x = 1
print("1, has it been executed?")


def t1():
     print("hello")
     print("2, has it been executed?")


def t2():
     print("world")
     print("3, has it been executed?")


def main():
     print("Hello World")
     print("4, has it been executed?")


print("5, has it been executed?")
print(x)

# while True:
# t2()

if x == 1:
     print("6, has it been executed?")

# test2.py

import test

当执行或运行test2.py时，运行结果:

1, has it been executed?

5, has it been executed?

1

6, has it been executed?

结论:当导入的模块没有添加if __name__=="__main__":时，当前模块将运行，导入模块中不在函数中的代码将按顺序执行，而函数中未调用的代码将不执行。

此外:

def main():
    # Put all your code you need to execute directly when this script run directly.
    pass

if __name__ == '__main__':
    main() 
else:
    # Put functions you need to be executed only whenever imported

你可以这样写"main.py":

#!/usr/bin/env python

__all__=["somevar", "do_something"]

somevar=""

def do_something():
    pass #blahblah

if __name__=="__main__":
    do_something()

虽然你不能在不运行代码的情况下使用import;有一种非常快速的方法可以输入你的变量;通过使用numpy。Savez，它将变量作为numpy数组存储在.npz文件中。然后，您可以使用numpy.load加载变量。

在scipy文档中可以看到完整的描述

请注意，这只适用于变量和变量数组，而不适用于方法等。

有一个Python增强提案PEP 299，旨在用def __main__:取代if __name__ == '__main__':习语，但它被拒绝了。在使用if __name__ = '__main__':)时，这仍然是一个很好的阅读来了解应该记住什么。