As the error message indicates, you have an unexpected indent error. This error occurs when a statement is unnecessarily indented or its indentation does not match the indentation of former statements in the same block. Python not only insists on indentation, it insists on consistent indentation . You are free to choose the number of spaces of indentation to use, but you then need to stick with it. If you indent one line by 4 spaces, but then indent the next by 2 (or 5, or 10, or ...), you'll get this error. Whenever you have a situation with code inside of a statement, that inside code must be indented, and must be indented consistently. It is used by the interpreter to know how to delimit blocks of instructions.