当使用带有True的While和返回列表的返回值时，“声明似乎无效”

Question

I'm a novice coder, trying to execute the below code in Python 3, IDE: Pycharm. For the line containing the code: opt_list[opt_choice] when I hover over that line of code, the message "Statement seems to have no effect" is popping up. When I execute the code, it shows me the Menu, takes the input. However, it just exits after that:

def remove_letter():       # Remove a selected letter from a string
    print("Remove letter")
    return

def num_compare():       # Compare 2 numbers to determine the larger
    print("Number compare")
    return

def print_string():      # Print the previously stored string
    print("Printing the saved String:")
    print(saved_string)
    return

def calculator():      # Basic Calculator(addition, subtraction, multiplication, division)
    print("Calculator")
    return

def accept_and_store():  # Accept and store a string
    print("Accept and store")
    global saved_string
    saved_string = str(input("Input Strings: "))
    return

def main(): # menu goes here
opt_list = [accept_and_store,
calculator,
print_string,
num_compare,
remove_letter]

while True:
print(”SELECT OPTION:”)
print(”1.\tAccept and Store”)
print(”2.\tCalculator”)
print(”3.\tPrint Stored String”)
print(”4.\tNumber Comparision”)
print(”5.\tLetter Remover”)
print(”6.\tQuit”)
opt_choice = int(input(”SELECTION: ”))
opt_choice -= 1
opt_list[opt_choice]

return

main()

Please find the output for your reference:

SELECT OPTION:
1.  Accept and Store
2.  Calculator
3.  Print Stored String
4.  Number Comparision
5.  Letter Remover
6.  Quit
SELECTION: 3

Process finished with exit code 0

Replacing the line of code:

opt_list[opt_choice]

with

opt_list[opt_choice]()

Gave me the following output, but again exited after providing after displaying the output:

SELECT OPTION:
1.  Accept and Store
2.  Calculator
3.  Print Stored String
4.  Number Comparision
5.  Letter Remover
6.  Quit
SELECTION: 1
Accept and store
Input Strings: hello

Process finished with exit code 0

Expected Functionality: I'm expecting it to be a continuous loop (since in while, the condition to check is provided as "True", and it will be always true!), taking my inputs, without exiting, since there is no exit code written for the loop to exit.

Answer 1

I could see 2 issues.

There is no indentation for the 2 functions. Other is the Double quotes for the print function. It seems to be a different character. ” instead of " below the While function.

def main(): # menu goes here
   opt_list = [accept_and_store,
               calculator,
               print_string,
               num_compare,
               remove_letter]

   while True:
     print("SELECT OPTION:")
     print("1.\tAccept and Store")
     print("2.\tCalculator")
     print("3.\tPrint Stored String")
     print("4.\tNumber Comparision")
     print("5.\tLetter Remover")
     print("6.\tQuit")
     opt_choice = int(input("SELECTION: "))
     opt_choice -= 1
     opt_list[opt_choice]