python基础语法（2）

 一、算术运算符

a = 21
b = 10
c = 1
d = 2

print(a + b)   #31
print(a - b)   #11
print(a * b)   #210
print(a / b)   #2.1
print(d ** c)  #2  幂
print(a % b)  #1  取余
print(a // b)  #2  取整--返回商的整数部分（向下取整）
print(9 // 2)  #4
print(-9 // 2)  #-5

 

二、比较运算符

三、赋值运算符

 

a = 21
b = 10
c = 1
d = 2

c += a   #c = c + a
print(c)

三、位运算符

 

 

四、逻辑运算符

 

a = 20
b = 10
c = 0

print(a and b)  #10
print(a or b) #20
print(not a) #false
print(c and b) #0
print(c or b) #10

 五、成员运算符

 

a = 10
b = 1
list = [1, 2, 3, 4, 5]

if (a in list):
    print("a in list")
else:
    print("a not in list")

if (a not in list):
    print("a not in list")
else:
    print("a in list")

六、身份运算符

 

a = 20
b = 20

print(id(a))
print(id(b))

if (a is b):
    print("1 - a 和 b 有相同的标识")
else:
    print("1 - a 和 b 没有相同的标识")

python运算符优先级

 

遗留问题：python中的变量内存地址分配？