When to use ' and " in strings for RE

Hi All,

I am a newbie to python. I have kick started python with Regular Expression. I am using Aptana Studio 3, build: 3.3.2.201302081546. Windows 7

My query is:
I have string "legal" and when I try to search "leg" or 'leg' both give me desired results(read 'as expected').
Can seniors please tell me?

Even if I use 'legal' and try to search "leg" or 'leg' again I will have both results.

Please help me.
Any help will be highly appreciated.