Regarding Python list output

Hi could someone please tell me why this code prints out the last item (“Phoebe Buffay”) on the list and not the whole list.

names = ["Joey Tribbiani", "Monica Geller", "Chandler Bing", "Phoebe Buffay"]
usernames = []

for name in names:
  usernames = name.replace(" ","_")

print(usernames)

Thank you.

Answer

You’re replacing the value of usernames each time and not appending to the list as you probably want:

names = ["Joey Tribbiani", "Monica Geller", "Chandler Bing", "Phoebe Buffay"]
usernames = []

for name in names:
  usernames.append(name.replace(" ","_"))

print(usernames)

This outputs what you expect:

['Joey_Tribbiani', 'Monica_Geller', 'Chandler_Bing', 'Phoebe_Buffay']

In your code, you’re not using the original usernames list to keep any data, instead you’re replacing what usernames is referring to for each iteration of the for loop – and after the for loop is finished, that’s the last element in your original list.