- consists of letters, numbers, and underscores, but cannot begin with a number;
- is case sensitive, that is In Python, Value and value are two different parameters; the
- underscore identifier has a special meaning.
Variable naming rules
- can only contain letters, numbers, underscores, numbers cannot begin;
- cannot use keywords and function names as variable names;
- The name of the variable should be known as it is as short as possible.
Value assignment does not require type declaration
can assign values to multiple variables at the same time
name,sex,age = ‘frank’,‘male’,18 ==> name = ‘frank’ sex = ‘male’ age = 18
3.Python reserved words
The following reserved words cannot be used as constants or variables, or any other identifier Name:
And , exec , notassert , finally , orbreak , for , passclass , from , printcontinue , globalraisedef , if , returndel , import , tryelif , in ,whileelse , is , with , except , lambda , yield
- print() The contents wrapped in three double quotes can be used for line feed output.
print(""" I have a jug of wine, Can comfort the wind. In the river, Give a drink to the world. """) ==> I have a jug of wine, Can comfort the wind. In the river, Give a drink to the world.
- end keyword, used to output the result on the same line, or add the required characters at the end of the output.
a, b = 0, 1 while b < 1000: print(b, end=',') a, b = b, a+b ==> 1,1,2,3,5,8,13,21,34,55,89,144,233,377,610,987,