The filename should be a string. In other names it should be within quotes.
f = open("D\\python\\HW\\2_1 - Copy.cp","r")
lines = f.readlines()
for i in lines:
thisline = i.split(" ");
You can also open the file using with
with open("D\\python\\HW\\2_1 - Copy.cp","r") as f:
lines = f.readlines()
for i in lines:
thisline = i.split(" ");
There is no need to add the semicolon(;) in python. It's ugly.