python-day04_02 算数运算符: + - * / // % **

# ### (1)算数运算符:  + - * / // % **

# +
var1 = 7
var2 = 90
res = var1 + var2
print(res)

# -
var1 = 7
var2 = 90
res = var1 - var2
print(res)

# *
var1 = 7
var2 = 10
res = var1 * var2
print(res)

# / 结果永远为小数
var1 = 10
var2 = 5
res = var1 / var2
print(res , type(res)) #2.0 <class 'float'>

# // 地板除
"""被除数 ➗ 除数 = 商"""
"""注意点:如果被除数或者除数是小数,那么得到正常结果之后,数值后面带上.0变成小数"""
var1 = 10.0
var2 = 3.0
# var2 = 3.0
res = var1 // var2 #(1)10 // 2 = 5;(2)10 // 3 = 3;(3)10 // 3.0 = 3.0
print(res)

# %  取余
var1 = 7
var2 = 4
res = var1 % var2
res = -7 % 4  # 1 = -(7%4)+4
res = 7 % -4  # -1 = (7%4) + (-4)
res = -7 % -4 # -3 (被除数和除数都是负的,正常结果加负号) -(7%4)
res = 81 % 7   # 4
res = 81 % -7  # -3=(81%7)+(-7)
res = -81 % 7  # 3=-(81%7)+7
res = -81 % -7 # -4=-(81%7)
print(res)

# ** 幂运算
res = 2 ** 3
print(res)  #2*2*2=8