如何从另一个程序在python中调用main函数中的变量？

Question

I have two python files first.py and second.py

first.py looks like

def main():
  #some computation
  first_variable=computation_result

second.py looks like

import first
def main():
  b=getattr(first, first_variable)
  #computation

but I am getting No Attribute error. Is there any way to access a variable inside main() method in first.py through second.py?

Answer 1

You should use function calls and return values instead of this.

Return the computation_result from the function in the first file, and then store the result in the b variable in the second file.

first.py

def main():
    # computation
    return computation_result

second.py

import first
def main():
    b = first.main()

Other option is to use a global variable in the first file where you will store the value and later reference it.

Answer 2

You will want to read 9.1 and 9.2 in the Tutorial and Naming and Binding in the Language Reference.

In your example first_variable only exists within first.main() 's local scope - while it is executing. It isn't accessible to anything outside of that scope.

---

You need to get first_variable into first 's global scope - then in second you can use it with first.first_variable .

One way would be to return something from first.main() and assign it to first_variable .

def main():
    return 2

first_variable = main()

Then in second you can use it:

import first
times_3 = first.first_variable * 3