如何修改一个文件中的变量并在另一个文件中使用它？

Question

I would like to:

• Declare a variable in one file
• Write its value in a second file
• Read its value in a third file

Here is my minimum example:

File "modify.py":

from declare import *
from use import *

array = [[0 for _ in range(2)] for _ in range(2)]
print("array:")
for row in array:
    print(row)

i_hate_python()
i_really_hate_python()

File "declare.py":

array = [[]]

def i_hate_python():
    print("array:")
    for row in array:
        print(row)

File "use.py":

from declare import *

def i_really_hate_python():
    print("array:")
    for row in array:
        print(row)

I am running the problem like so:

python modify.py

The output is:

array:
[0, 0]
[0, 0]
array:
[]
array:
[]

I would like the output to be:

array:
[0, 0]
[0, 0]
array:
[0, 0]
[0, 0]
array:
[0, 0]
[0, 0]

Thanks in advance for not leaving any comments about how I must be designing my program badly.

Answer 1

array = [[0 for _ in range(2)] for _ in range(2)]

That line of code in modify.py recreates array as a local variable, and you've lost the imported variable of the same name.

Try this instead:

import declare
declare.array = ...

By prefixing declare. to the variable name, you keep the association with its containing module.