Python 逻辑运算符，not in，in

一、逻辑运算符

and     or   not       

优先级 （） > not > and > or

print(4 > 3 or 4 < 3 and 1!=1)
print(2 > 1 and 3 < 4 or 4 > 5 and 2 < 1)
print(1 > 2 and 3 < 4 or 4 > 5 and 2 > 1 or 9 < 8)
print(1 > 1 and 3 < 4 or 4 > 5 and 2 > 1 and 9 > 8 or 7 < 6)
print(not 2 > 1 and 3 < 4 or 4 > 5 and 2 > 1 and 9 > 8 or 7 < 6)

print(4 or 3)
print(2 or 3)
print(1 or 3)
print(0 or 3)
print(-1 or 3)

print(x or y), 如果 x 为真，则值为x，否则为y
print(x or y), 如果 x 为真，则值为y，否则为x

print(4 and 3)
print(2 and 3)
print(1 and 3)
print(0 and 3)
print(-1 and 3)

print(x and y) 和 or 相反

print( 2>3 or 3)
print( 2>2 or 0)
print( 2>3 or 3)

3 > 2  打印 True

二、bool 与 int 转换

  bool 转换成 int 只有 0 和1

  int 转换成 bool ，0为False，其他所有为True

三、in         not  in

str = 'abcdefghijklmn'
print('a' in str)
print('bcde' in str)
print('bm' in str)

comment = input('Please enter comment：')
if '台独' in comment:
    print('Your comments contain illegal characters!')
else：print('Comments increasing success')