What is the scope of variables in function declarations

Question

Why can't I change the variable reminder at

reminder = "oops"

In this code:

def ask_ok(prompt, retries=4, reminder='Please try again!'):
    while True:
        ok = input(prompt)
        if ok in ('y', 'ye', 'yes'):
            reminder = "oops"
            return True
        if ok in ('n', 'no', 'nop', 'nope'):
            return False
        retries = retries - 1
        if retries < 0:
            raise ValueError('invalid user response')
        print(reminder)

ask_ok("what")

ask_ok("again")

You're returning from the function after you change it. So the assignment has no effect. — Barmar, Jul 01 '22 at 04:51
Are you trying to change the default? You can't do that by assigning to the variable. — Barmar, Jul 01 '22 at 04:51

score 1 · Accepted Answer · answered Jul 01 '22 at 04:54

You can't change the default value of the parameter by assigning to it. Assigning to it just changes its value in the current call, it's not a permanent change to the function.

If you want a persistent variable, use a global variable.

reminder = 'Please try again!'

def ask_ok(prompt, retries=4):
    global reminder
    while True:
        ok = input(prompt)
        if ok in ('y', 'ye', 'yes'):
            reminder = "oops"
            return True
        if ok in ('n', 'no', 'nop', 'nope'):
            return False
        retries = retries - 1
        if retries < 0:
            raise ValueError('invalid user response')
        print(reminder)

What is the scope of variables in function declarations

1 Answers1