Variable names can be any combination of letters, numbers or underscore
The first character variable names can not be digital
The following keywords can not be declared variable name
['and', 'as', 'assert', 'break', 'class', 'continue', 'def', 'del', 'elif', 'else', 'except', 'exec', 'finally', 'for', 'from', 'global', 'if', 'import', 'in', 'is', 'lambda', 'not', 'or', 'pass', 'print', 'raise', 'return', 'try', 'while', 'with', 'yield']
And built-in Python it is best not to repeat things such as: sum method
Hump body