我有一个我正在构建的Python程序，可以以两种方式之一运行:第一种是调用Python main.py，它会以友好的方式提示用户输入，然后通过程序运行用户输入。另一种方法是调用python batch.py -file-它将传递所有友好的输入收集，并通过程序一次性运行整个文件的输入值。
问题是，当我运行batch.py时，它从main.py中导入了一些变量/方法/等，当它运行以下代码时:
import main
在程序的第一行，它立即出错，因为它试图运行main.py中的代码。
如何阻止Python运行我正在导入的主模块中包含的代码?
当前回答
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
其他回答
试着从main.py导入所需的函数?所以,
from main import SomeFunction
可能是你在batch.py中命名的函数与main.py中的函数相同，当你导入main.py时，程序运行main.py函数而不是batch.py函数;执行上述操作可以解决这个问题。我希望。
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()
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。
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。
使用if __name__ == '__main__'习惯用法——__name__是一个特殊变量，如果模块作为脚本运行，其值为'__main__'，如果模块被导入，则为模块名。所以你会这样做
# imports
# class/function definitions
if __name__ == '__main__':
# code here will only run when you invoke 'python main.py'
