问试图理解流程控制/图表绘制

EN

import sys

bol_access_denied = False  # You will need to introduce a flag before you enter your while...loop.
access = False
while not access:
    username = input('Enter username: ')
    if username.lower() != 'joe':
        print("imposter!")
        continue
    
    # else:  # This else can be omitted since program flows here ONLY when username == joe 
    print(f'Hello {username.capitalize()}')
    for i in range(3):
        password = input('Enter password: ')
        if password == 'Water':
            access = True
            break
    else:
        print("3 strikes, you're out")
        bol_access_denied = True  # set the flag here.
        # sys.exit()  This can be replaced by 'break', then backed by [see STEP Final-Check]
    if bol_access_denied:  # Test the flag here.
        break

if access:  # STEP Final-Check, is to navigate the user to a personalized section of your program.
    print("Access granted")

# Your program ends here naturally without explicitly invoking the exit function.