python的in，is和id函数，,1. in 和 no

python的in，is和id函数，,1. in 和 no

1. in 和 not in ——判断某个序列中是否存在某值

# inaa = [1,2,3,‘Cathy‘,‘太平洋‘]if ‘大西洋‘ in aa:    print(‘yes‘)else:    print(‘no‘)  # no# not inif ‘大西洋‘ not in aa:    print(‘yes‘)  # yeselse:    print(‘no‘)    #-------------------------------------------------------# 判断字符串是否存在某子串    if ‘马来西亚‘ in ‘马来西亚是一个太平洋国家‘:       print(‘of course‘) # 输出 ‘of course‘# ------------------------------------------------------if 0 in (0,1,2,3):    print(‘hhhh‘) #输出 ‘hhhh‘if 0 in [0,1,2,3]:    print(‘kkkk‘) #输出 ‘hhhh‘

2. is 和 is not ——判断两个标识符是不是指向同一个地址（同一个对象），类似于判断 id(x) == id(y)

# 相同bb = 234cc = 234if bb is cc:    print(‘bb is cc‘)  #结果是 bb is cc else:    print(‘bb is not cc‘)print(id(bb))  # id()值一样print(id(cc))# 相同bb = ‘hhh‘cc = ‘hhh‘if bb is cc:    print(‘bb is cc‘)  #结果是 bb is cc else:    print(‘bb is not cc‘)    # 相同bb = ‘hhh‘cc = bbif bb is cc:    print(‘bb is cc‘)  #结果是 bb is cc else:    print(‘bb is not cc‘)print(id(bb))  # id()值一样print(id(cc))# 相同bb = [1,2,3]cc = bbif bb is cc:    print(‘bb is cc‘)  #结果是 bb is cc else:    print(‘bb is not cc‘)# 不相同bb = [1,2,3]cc = [1,2,3]if bb is cc:    print(‘bb is cc‘)   else:    print(‘bb is not cc‘) #结果是 bb is not ccprint(id(bb))  # id()值不一样print(id(cc))

3. id() 函数，获取对象的内存地址（不同电脑不一样），例如：

bb = ‘hhh‘cc = bbif bb is cc:    print(‘bb is cc‘)  #结果是 bb is cc else:    print(‘bb is not cc‘)print(id(bb))  # id()值一样，均为 1680346901336print(id(cc))

参考：

https://www.runoob.com/python/python-func-id.html

https://blog.csdn.net/zhangvalue/article/details/94598781

python的in，is和id函数