Python (ii) Python basic data type

variables

A variable is an area in memory

The name of a variable: A number that consists of letters, numbers, underscores, and cannot begin with

The address variable in Python is the opposite of the C language, and a single piece of data contains multiple tags:

>>> a=1
>>> b=1
>>> ID (a)
34909288
>>> ID (b)
34909288
Integral type

Note: type () can view data types

>>> num1=123
>>> type (NUM1)
<type 'int' >
Long integer type

#强制定义为长整型: num3=999l

>>> num2=9999999999999999999
>>> type (num2)
<type 'long' >

>>> num3=999l
>>> type (NUM3)
<type ' Long ' >
Floating point Type

#1.2e10 represents a value of 1.2 for 10 times;
#12e9代表的数值为12的9次方;

>>> f1=12.0
>>> Type (F1)
<type ' float ' >
>>> F2=1.2e10
>>> type (F2)
<type 'float' >
Plural type

#python对复数提供内嵌支持, eg:3.14j, 8.32e-36j

>>> c=3.14j
>>> type (c)
<type 'complex' >
Operators and expressions

Arithmetic operators: +,-, *,**,/,%,//

Python (ii) Python basic data type