Python's operators and expressions

The Python operator is associated with an expression 1. Operator classification

The operators are divided into 5 main types:

1. 算术运算符 2. 比较运算符3. 位运算符4. 逻辑运算符 5. 成员运算符 6. 身份运算符7. 赋值运算符

1. Arithmetic operators

算术运算符    描述                     实例                输出结果 +       两个对象相加                 abc+d                abcd -       两个对象相减                 5-2                  3 *       两个对象相乘                 3*ab                 ababab /       两个对象相除                 8/2                  4    %       取模,返回除法的余数           5%3                  2 **      幂                          2**3                 8 //      取整除，返回商的整数部分       3//2                 1

2. Comparison operators

比较运算符   描述                      实例                 输出结果 ==      等于                        abc==abc             True !=      不等于,与<>意思一样           abc!=ab              True <       小于                        5<6                  True <=      小于等于                     5<=6                True  >       大于                        5>6                  False >=      大于等于                     5>=6                False

3. Bitwise operators

位运算符       描述                         实例            输出结果        按位与运算符:参与运算的两个     &      值，二进制位都为1，则该位的          60&13              12        结果为1，否则为0          |      按位或运算符：参与运算的两个        值，二进制位只要有一个为1时,         60|13              61        结果位就为1 ^      按位异或运算符:参与运算的两        个值，二进制位不同时，该位的          60^13             49        结果为1 ~      按位取反运算符:参与运算的值,        二进制位取反，0变1，1变0             ~60              -61 <<     左移动运算符:参与运算的值，        所有二进制位左移动指定位数           60<<2             240 >>     右移动运算符:参与运算的值，        所有二进制位右移动指定位数           60>>3              7     

4. Logical operators

逻辑运算符       描述                       实例               输出结果 and      布尔"与":当两个值都为真,        a and b         当a,b均为True,则结果为True          结果才为真,否则均为假                            or       布尔"或":当两个值有一个         a or b          当a,b有一个为True,则结果为True          为真，结果就为真 not      布尔"非":当值为假时，结         not a           当a为False,则结果为True          果才为真

5. Member Operators

成员运算符      描述                       实例               输出结果 in       如果指定的对象中包含该成       ‘a‘ in ‘abc‘           True          员,则返回True,否则False not in   如果指定的对象中不包含该成     ‘c‘ not in ‘abc‘       True          员,则返回True,否则False

6. Identity operator

身份运算符      描述                       实例               输出结果 is       判断两个标识符是否是同一       ‘abc‘ is ‘abc‘         True          对象,如果是,则返回True is not   判断两个标识符是否不是同       ‘ab‘ isa not ‘abc‘     True          一对象,如果不是,则返回True   

7. Assignment operator (a=10)

赋值运算符        描述               实例               输出结果 +=          加法赋值运算符          a += 2              a=12 -=          减法赋值运算符          a -= 2              a=8 *=          乘法赋值运算符          a *= 2              a=20 /=          除法赋值运算符          a /= 2              a=5 %=          取模赋值运算符          a %= 3              a=1 //=         地板除赋值运算符        a //= 3             a=3 **=         幂赋值运算符            a **= 3            a=1000

Note: all assignment operations can be converted to (variable = variable arithmetic operator value) format.

赋值运算：    a += 2算术运算：    a = a + 2

2. Operator Precedence

Operator description priority (lower priority from top to bottom) ' Expression,... '         String Conversion 1{key,datum,...}        Dictionary display 2[expression,...]        List Display 3 (expression,...)        binding or tuple display 4f (arguments,...)                       function call 5x[index:index] Addressing segment 6x[index] subscript (that is, index)                           7x.attribute attribute Reference 8** exponent (power)                             9~x rollover 10+x,-X plus sign 11*,/,% multiplication, division, modulo 12+,-addition, subtraction 13&lt                         ; <, >> left (right) bit move 14& bitwise AND operation                       15^ bitwise XOR OR Operation 16| Bitwise OR operation                         17<,<=,>,>=,==,!= comparison size operation 18is, is not identity operation                       19in, not in member Operation 20not x boolean "non" operation                       21and boolean "and" Arithmetic 22or boolean "or" Operation 23lambda Lambda Expression 24

Note: It is not recommended to prioritize rote operators, and it is recommended to use () to solve the priority problem in practice.

Detection data Attribution type (A=100)

1. type" () test can be used, in development try to avoid using this method

     format: type (variable) b = Type (a) print (b) #<class ' int ';  

2. isinstance () detects whether a data is created by the specified type

     format: isinstance (variable, class) b = Isinstance (a,int) print (b) #True  

Note: It is forbidden to detect whether any data is created by the object class because everything in Python is an object.

Python's operators and expressions