Assembled by Adam Whaley, Original Text: How to Think like a Computer Scientist., Original Text: Problem Solving with Algorithms and Data Structures, Original Text: Python for Everybody - Interactive
If you are using a text editor to write your scripts, you might run into problems with spaces and tabs. The best way to avoid these problems is to use spaces exclusively (no tabs). Most text editors that know about Python do this by default, but some donโt.
Also, donโt forget to save your program before you run it. Some development environments do this automatically, but some donโt. In that case, the program you are looking at in the text editor is not the same as the program you are running.
Make sure that the code that youโre looking at is the same code that youโre running. If youโre not sure, put something like print("hello") at the beginning of the program and run it again. If you donโt see hello, youโre not running the right program!