python basis (variable)

1. Variables

　　1) variables can only be made: letters, numbers, underscores

　　2) can not start with a number

　　3) can not be used pyhon Keywords: such as class, public, and, as, assert, break

　　4) best not to repeat things and built-in python (sum)

　　Naming convention: user_id (between words separated by _) python

　　　　　　　userId (camel named) C #, Java

 

PS: python variables need to declare the variable type