Python运算符，,Python语言支持

Python运算符，,Python语言支持

Python语言支持以下类型的运算符：

l 算术运算符l 比较运算符l 赋值运算符l 逻辑运算符l 位运算符l 成员运算符l 身份运算符l 运算符优先级

Python算术运算符

/***arithmetic.py***/a = 21b = 10c = 0c = a + b print "1 - c is : ", cc = a - bprint "2 - c is : ", cc = a * bprint "3 - c is : ", c c = a / bprint "4 - c is : ", cc = a % bprint "5 - c is : ", c#change the value of a,b,ca = 2b = 3c = a ** bprint "6 - c is : ", ca = 10b = 5c = a // bprint "7 - c is : ", c

运行结果：

robot@ubuntu:~/wangqinghe/python/20190821$ vim arithmetic.py

robot@ubuntu:~/wangqinghe/python/20190821$ python arithmetic.py

1 - c is : 31

2 - c is : 11

3 - c is : 210

4 - c is : 2

5 - c is : 1

6 - c is : 8

7 - c is : 2

注意：在python2.x里，整数除以整数，只能的到整数，如果想要得到小数部分，把其中一个数改为浮点数即可

/***inter.py***/print 1/2print 1.0/2print 1/float(2)

运行结果：

robot@ubuntu:~/wangqinghe/python/20190821$ vim inter.py

robot@ubuntu:~/wangqinghe/python/20190821$ python inter.py

0

0.5

0.5

Python比较运算符

/***comparsion.py****/a = 21b = 10c = 0if a == b :    print "a == b"else:    print "a no == b"if a != b :    print "a != b"else:    print "a no != b"if a <> b :    print "a <> b"else :    print "a no <> b"if a < b :    print "a < b"else :    print "a no < b"if a > b :    print "a > b"else :    print "a no > b"a = 5b = 20if a <= b :    print "a <= b"else :    print "a no <= b"if b >= a :    print "b <= a"else :    print "b no <= a"

运行结果：

robot@ubuntu:~/wangqinghe/python/20190821$ python comparsion.py

a no == b

a != b

a <> b

a no < b

a > b

a <= b

b <= a

Python赋值运算符：

/***assignment.py***/a = 21b = 10c = 0c = a + bprint "a + b = " , cc += aprint "a + b = " , cc *= aprint "a + b = " , cc /= aprint "a + b = " , cc = 2c %= aprint "a + b = " , cc ** aprint "a + b = " , cc //= aprint "a + b = " , c

运行结果：

robot@ubuntu:~/wangqinghe/python/20190821$ python assignment.py

a + b = 31

a + b = 52

a + b = 1092

a + b = 52

a + b = 2

a + b = 2

a + b = 0

Python位运算符

Python逻辑运算符

按位运算符把数字看作二进制进行计算的。python中按位运算法则如下：

/***bit.py***/a = 60b = 13print a,bprint a & bprint a | bprint a ^ bprint ~aprint a << 2print b >> 2

运行结果：

robot@ubuntu:~/wangqinghe/python/20190821$ python bit.py

60 13

12

61

49

-61

240

3

Python逻辑运算符

/***bool.py***/a = 10 b = 20if a and b :    print "a and b is true"else :    print "a and b is not true"if a or b :    print "a or b is true"else :    print "a or b not true"a = 0if a and b :    print "a and b is true"else :    print "a and b is not true"if a or b :    print "a or b is true"else :    print "a or b not true"if not(a and b) :    print "a and b all true"else :    print "a and b not all true"

运行结果：

robot@ubuntu:~/wangqinghe/python/20190821$ python bool.py

a and b is true

a or b is true

a and b is not true

a or b is true

a and b all true

Python成员运算符

/***member.py***/a = 10b = 20list = [1,2,3,4,5];if ( a in list ) :    print "a in list"else :    print "b not in list"if(b not in list):    print "b not in list"else :    print "b on list"a = 2if ( a in list ) :    print "a in list"else :    print "b not in list"

运行结果：

robot@ubuntu:~/wangqinghe/python/20190821$ python member.py

b not in list

b not in list

a in list

Python身份运算符：

身份运算符用于比较两个对象的存储单元

注：id()函数用于获取对象内存地址

/***id.py***/a = 20b = 20if( a is b):    print "a and b are equal id"else:    print "a and b are not equal id"if ( a is not b):    print "a is not b"else:    print "a is b"b = 30if( a is b):    print "a and b are equal id"else:    print "a and b are not equal id"if ( a is not b):    print "a is not b"else:    print "a is b"

运行结果：

robot@ubuntu:~/wangqinghe/python/20190821$ python id.py

a and b are equal id

a is b

a and b are not equal id

a is not b

is 和 == 的区别：

is是用于判断两个变量引用对象是否是同一个（同一块内存空间），==用于判断引用变量的值是否相同。

Python运算符优先级

运算符	描述
**	指数（最高优先级）
~、+、	按位反转、一元加号、和减号(最后两个的方法名位+@和-@)
*/%//	乘、除、取模、取整除
+-	加法减法
>> <<	右移、左移
&	与运算
^|	异或、或
<= 、 <、> 、 >=	比较运算符
<> 、 == 、 ！=	等于运算符
= %= /= //= -= += *= **=	赋值运算符
is is not	身份运算符
in not in	成员运算符
not and or	逻辑运算符

Python运算符