#_*_coding:utf-8_*_ # 基本运算符 # 以下假设变量 a = 10, b = 20 # 算术运算 ''' print(a + b) # 30 print(a - b) # -10 print(a / b) # 0.5 print(a // b) # 0 print(a % b) # 10 print(2 ** 3) # 8 2的三次方 ''' # 比较运算 ''' 比较运算:只能在同类型之间进行,其中int与float同属于数字类型 (统称 无数字类型) print(10 > 3.1) # True print(10 >= 10) # True (<,<=,同上) print(a == b) #False print(a != b) #True print(a <> b) #True ''' # 赋值运算 ''' # 增量赋值 age = 18 age = age +1 age += 1 print(age) # 20 # -=, *=, /=, %=, **=, //= # 链式赋值 x = 1 y = x z = x x = y = z = 1 print (id(x),id(y),id(z)) #4538100736 4538100736 4538100736 #id相同 # 交叉赋值 a = 10 b = 20 a,b = b,a print(a, b) # 20 10 # 解压赋值 age = [10,11,12] boy1 = age[0] boy2 = age[1] boy3 = age[2] boy1,boy2,boy3 = age *等号右面包含的值的个数必须与等号左边变量名的个数一致 print(boy1,boy2,boy3) # 10 11 12 boy1,_,_= age # _ 充当占位符 boy1,*_ = age # *_无穷多个 print(boy1) # 10 ''' # 逻辑运算 ''' 逻辑运算:and, or, not and : 连接左右两个条件,两个条件必须都成立,最后结果为True 从左往右运算,只要有条件为假,此条件之后的条件不运算 or : 连接左右两个条件,两个条件只要有一个成立,结果就为True 从左往右运算,只要有条件为真,此条件之后的条件不运算 not :取反 e.g. print((not 1>3 and (False or True)) or (False and True)) # True ''' # 身份运算 ''' is 与 == '''