python列表常用功能介绍

names = [] #定义空列表 names = ['a','b','c'] #定义非空列表

>>> names = ['a','b','c','d'] >>> names[0] #访问第一个元素 'a' >>> names[1] #访问第二个元素 'b' >>> names[-1] #访问倒数第一个元素 'd' >>> names[-2] #访问倒数第二个元素 'c'

>>> names = ['a','b','c','d'] >>> names[1] = '1' #对第二个元素进行修改 >>> names ['a', '1', 'c', 'd']

>>> li = ['a','b','c','d'] >>> li[1:3] #取第二个到第四个之间的元素，包括第二个，不包括第四个 ['b', 'c'] >>> li[1:-1] #取第二个到最后一个之间的元素，包括第二个，不包括最后一个 ['b', 'c'] >>> li[0:3] #取第一个到第四个之间的元素，包括第一个，不包括第四个 ['a', 'b', 'c'] >>> li[:3] #取第一个到第四个之间的元素，同上 ['a', 'b', 'c'] >>> li[3:] #取第四个元素 ['d'] >>> li[-1:] #取最后一个元素 ['d'] >>> li[0::2] #从第一个元素开始，跳着一个取元素 ['a', 'c'] >>> li[::2] #同上 ['a', 'c']

>>> names = ['a','b','c','d'] >>> names.append('e') >>> names ['a', 'b', 'c', 'd', 'e']

>>> names = ['a','b','c','d','a'] >>> names.count('a') #统计'a'元素的个数 2

>>> names1 = ['a','b','c','d'] >>> names2 = [1,2,3,4] >>> names1.extend(names2) >>> names1 ['a', 'b', 'c', 'd', 1, 2, 3, 4]

>>> names = ['a','b','c','d'] >>> names.index('a') 0

>>> names = ['a','b','c','d'] >>> names.insert(0,'1') #0表示需要插入的下标值，'1'表示插入的内容 >>> names ['1', 'a', 'b', 'c', 'd'] #在下标值为0的地方插入'1'

#根据下标值删除元素 >>> names = ['a','b','c','d'] >>> del names[0] >>> names ['b', 'c', 'd'] #根据元素删除 >>> names = ['a','b','c','d'] >>> names.remove('a') >>> names ['b', 'c', 'd'] #删除最后一个 >>> names = ['a','b','c','d'] >>> names.pop() 'd' >>> names ['a', 'b', 'c']

>>> names = ['a','b','c','d'] >>> names.reverse() >>> names ['d', 'c', 'b', 'a'] #将整个列表翻转过来

>>> names = [4,2,3,1] >>> names.sort() >>> names [1, 2, 3, 4]