Coming from a C# background the naming convention for variables and methods are usually either camelCase or PascalCase:
// C# example
string thisIsMyVariable = "a"
public void ThisIsMyMethod()
In Python, I have seen the above but I have also seen snake_case being used:
# python example
this_is_my_variable = 'a'
def this_is_my_function():
Is there a more preferable, definitive coding style for Python?
There is PEP 8, as other answers show, but PEP 8 is only the styleguide for the standard library, and it's only taken as gospel therein. One of the most frequent deviations of PEP 8 for other pieces of code is the variable naming, specifically for methods. There is no single predominate style, although considering the volume of code that uses mixedCase, if one were to make a strict census one would probably end up with a version of PEP 8 with mixedCase. There is little other deviation from PEP 8 that is quite as common.
The coding style is usually part of an organization's internal policy/convention standards, but I think in general, the all_lower_case_underscore_separator style (also called snake_case) is most common in python.