Coming from a C# background the naming convention for variables and method names are usually either camelCase or PascalCase:
        
As mentioned, PEP 8 says to use lower_case_with_underscores for variables, methods and functions.
I prefer using lower_case_with_underscores for variables and mixedCase for methods and functions makes the code more explicit and readable.  Thus following the Zen of Python's "explicit is better than implicit" and "Readability counts"