Learning Python, newbie question about strings and evaluation

[Larz60+]

first, you need to pass comp_colour as an argument:

def computer_plays(comp_colour):

Now your if statement is true if comp_colour is 'black) # true if not = 'white'
for is comp_colour == 'black' it's != 'white' so change 'black' to 'black'
You're getting your logic messed up.
I think what you're saying you want is:

if comp_colour == "white": #it could be a tie
    comp_colour = "black"