Calling different functions by same name, having same action

Question

I was wondering about ways to add new lines to already running code (it could even be a simple while loop) and run it. But this way of creating and importing a class or functions always runs the first added lines of code even if you have changed the function and imported it again. I tried adding del main, and replacing the line data = main(data) with data = main(data).copy(), but both haven't given any result. Any error or log does not occur, I added info in the steps for understanding.

CODES:

def applyCommand(data, command):
    with open('/$PATH/simple_macro.py', 'w') as file:
        file.write(command)
        print('[INFO] simple macro has been written- step 1 ✓.')

    from simple_macro import main
    print('[INFO] simple macro has been imported - step 2 ✓.')
    
    data = main(data)
    print('[INFO] data has been updated - step 3 ✓.')

    from os import remove
    remove('/$PATH/simple_macro.py')
    print('[INFO] simple macro file has been deleted - step 4 ✓.')
   
    return data

data = list(range(10))

command = "def main(data):\n    return data[:5]"
data = applyCommand(data, command)
print("Updated data:", data)

commandTwo = "def main(data):\n    return data[0]"
data = applyCommand(data, commandTwo)
print("Updated data:", data)

OUTPUT:

[INFO] simple macro has been written- step 1 ✓.
[INFO] simple macro has been imported - step 2 ✓.
[INFO] data has been updated - step 3 ✓.
[INFO] simple macro file has been deleted - step 4 ✓.
Updated data: [0, 1, 2, 3, 4]
[INFO] simple macro has been written- step 1 ✓.
[INFO] simple macro has been imported - step 2 ✓.
[INFO] data has been updated - step 3 ✓.
[INFO] simple macro file has been deleted - step 4 ✓.
Updated data: [0, 1, 2, 3, 4]

The first part produces the correct expected output, but the second one's expected output is just 0 but the actual output is [0, 1, 2, 3, 4] as you see. So the question is what type of addition or change can be done to that code cells to get expected output after the first call?

Answer 1

Running, importing and changing the same function and program in a single run, will leave the original created main() in the memory of your computer. In order to properly refresh the import, you need to use reload() from the importlib module:

from importlib import reload
import os
def applyCommand(data, command):
    with open('simple_macro.py', 'w') as file:
        file.write(command)
        print('[INFO] simple macro has been written- step 1 ✓.')

    import simple_macro
    reload(simple_macro)
    with open('simple_macro.py') as file:
        print(file.read())
    print('[INFO] simple macro has been imported - step 2 ✓.')
    
    data = simple_macro.main(data)
    print('[INFO] data has been updated - step 3 ✓.')
    
    os.remove('simple_macro.py')
    print('[INFO] simple macro file has been deleted - step 4 ✓.')
   
    return data

data = list(range(10))

command = "def main(data):\n    return data[:5]"
data = applyCommand(data, command)
print("Updated data:", data)

commandTwo = "def main(data):\n    return data[0]"
data = applyCommand(data, commandTwo)
print("Updated data:", data)

Results:

[INFO] simple macro has been written- step 1 ✓.
def main(data):
    return data[:5]
[INFO] simple macro has been imported - step 2 ✓.
[INFO] data has been updated - step 3 ✓.
[INFO] simple macro file has been deleted - step 4 ✓.
Updated data: [0, 1, 2, 3, 4]
[INFO] simple macro has been written- step 1 ✓.
def main(data):
    return data[0]
[INFO] simple macro has been imported - step 2 ✓.
[INFO] data has been updated - step 3 ✓.
[INFO] simple macro file has been deleted - step 4 ✓.
Updated data: 0

I added a print of the actual change made to simple_macro.