How to debug indentation errors in python

Question

I am trying to write my very first python script. This was working but then after some slight refactoring I have, apparently, broken the indentation. I can not determine what is the problem. The interpretor complains about the following method. Can someone point it out?

def dataReceived(self, data):
    a = data.split(':')
    print a
    if len(a) > 1:
        command = a[0]
        content = a[1]

        msg = ""
        if command == "iam":
            self.name = content
            msg = self.name + " has joined"

        elif command == "msg":
            msg = self.name + ": " + content
            print msg

The error reads: File "python_server.py", line 17 a = data.split(':') ^ IndentationError: expected an indented block

Answer 1

I encountered a similar problem using Sublime Text 2.

To solve, click on the "Tab Size" at the bottom of the editor, and choose "Convert Indentation to Tabs".