Python -- 逻辑运算符 -- and -- if语句

import keyword
print(keyword.kwlist)


# ['False', 'None', 'True', 'and', 'as', 'assert', 'async', 'await', 'break',
#  'class', 'continue', 'def', 'del', 'elif', 'else', 'except', 'finally',
#  'for', 'from', 'global', 'if', 'import', 'in', 'is', 'lambda', 'nonlocal',
#  'not', 'or', 'pass', 'raise', 'return', 'try', 'while', 'with', 'yield']

# a = 5
# b = 10
# c = 6
# print(a != b)
# print(a<b and  b<c)

# print(1>2 and 3 < 4 or 4>5 and 2 > 1 or 9< 8)

# 优先级  () not and or
# x or y   x为真就是x  否y
# x and y  x为真就是y  否x
# not x    x为真就是false 否 true

# in   在什么什么里面
# not in  不在什么什么里面
print('ni' not in 'nihaoma')

# 三元运算符
#  结果1 if 条件 else 结果2    true就是 if左边的  否  右边
re = 55 if 3 > 2 else 66
print(re)

print('if' in keyword.kwlist)





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import keyword
# print('if' in keyword.kwlist)   #查看if是否是关键字
# if 表达式 :

# if 5<3 :
#     print('张飞')
# print('李艳')

# if 条件:
#     pass
# else:
#     pass

# a,b=5,3
# if a>b :
#     print(a)
# else:
#     print(b)

#     嵌套if

a,b,c = 5,3,2

# if a>b:
#     if a>c:
#         print(a)
#     else:
#         print(c)
# else:
#     if b>c:
#         print(b)
#     else:
#         print(c)

#   多重判断
# score = 99;
# if score >= 0 and score <= 60:
#     print('及格')
# elif score >= 61 and score <= 80:
#     print('良好')
# elif score >=81 and score <=100:
#     print('优秀')

if len('1') > 3:
    print('长')

if 'nihao'.startswith('ni'):    #以什么开头startswith
    print(True)

if (i := 5) < 3:
    print(i)

if (n := len(a)) > 3 :
    print('你好')