#!/usr/bin/env python #Python 3.7.0 列表常用方法 __author__ = "lrtao2010" #创建列表 # a = [] # b = [1,2,3] # c = list('123') # print(a) # print(b) # print(c) # [] # [1, 2, 3] # ['1', '2', '3'] #list()将其他类型转换成列表 # a = list('123') # b = list('thisistest') # c = list('this is test') # print(a) # print(b) # print(c) # ['1', '2', '3'] # ['t', 'h', 'i', 's', 'i', 's', 't', 'e', 's', 't'] # ['t', 'h', 'i', 's', ' ', 'i', 's', ' ', 't', 'e', 's', 't'] # a = list(123) # print(a) # a = list(123) # TypeError: 'int' object is not iterable #使用[offset]获取元素 或 修改元素,数组越界会报错 #a = ['a1','b1','c1'] # print(a[1]) # b1 # a[1] = 'd1' # print(a) # ['a1', 'd1', 'c1'] # print(a[3]) # print(a[3]) # IndexError: list index out of range #列表切片与提取元素list[start:end:step] # a = list('abcdefghijk') # v1 = a[2:3] # v2 = a[2:] # v3 = a[:] # v4 = a[0:6:2] # print(v1) # print(v2) # print(v3) # print(v4) # ['c'] # ['c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k'] # ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k'] # ['a', 'c', 'e'] #append(self, *args, **kwargs) 添加元素至尾部 # a = ['a','b'] # a.append('c') # print(a) # ['a', 'b', 'c'] #insert(self, *args, **kwargs)在指定位置插入 # a = ['a',['a','b']] # a.insert(0,'c') # a[2].insert(0,'c') # a.insert(-1,'append') # print(a) # ['c', 'a', 'append', ['c', 'a', 'b']] #clear(self, *args, **kwargs)清空列表 # a = ['a','b'] # a.clear() # print(a) # [] #copy (影子)复制，只拷贝第一层，2层以上,都是拷贝元素的地址，浅复制 # a = ['a',['b']] # b = a.copy() # c = a # d = a[:] # a.append('d') # a[1].append('c') # print(a) # print(b,b is a, b == a ) # print(c,c is a, c == a ) # print(d,d is a, d == a ) # ['a', ['b', 'c'], 'd'] # ['a', ['b', 'c']] False False # ['a', ['b', 'c'], 'd'] True True # ['a', ['b', 'c']] False False # 深复制 # import copy # a = ['a',['b']] # b = copy.deepcopy(a) # a.append('d') # a[1].append('c') # print(a) # print(b) # ['a', ['b', 'c'], 'd'] # ['a', ['b']] #count 统计指定值出现的次数 # a = ['a','b','a',['a','b','ab'],'ab'] # v1 = a.count('a') # v2 = a[3].count('b') # print(v1,v2) # 2 1 #extend(self, *args, **kwargs) 合并列表同+= # a = ['a'] # b = ['b'] # a.extend(b) # print(a,b) # ['a', 'b'] ['b'] # a = ['a'] # b = ['b'] # a += b # print(a,b) # ['a', 'b'] ['b'] # index(self, *args, **kwargs)查找指定值的位置，不存在会报错 # a = ['a','b'] # v = a.index('b') # print(v) # 1 # a = ['a','b'] # v = a.index('c') # print(v) # v = a.index('c') # ValueError: 'c' is not in list #使用in判断值是否存在列表 # a = ['a'] # v1 = 'a' in a # v2 = 'b' in a # print(v1,v2) # True False # pop(self, *args, **kwargs) 返回某个元素后，并在数组里删除它。默认删除最后一个元素 # a = ['1','2','3'] # v = a.pop() # print(a,v) # ['1', '2'] 3 # a = ['1','2','3'] # v = a.pop(1) # print(a,v) # ['1', '3'] 2 #remove(self, *args, **kwargs) 删除最先找到的元素，找不到会抛异常 # a = ['1','2','3','2'] # v = a.remove('2') # print(a,v) # ['1', '3', '2'] None # a = ['1','2','3','2'] # v = a.remove('0') # print(a,v) # v = a.remove('0') # ValueError: list.remove(x): x not in list #reverse(self, *args, **kwargs)将列表翻转 # a = ['1','4','2','3','5'] # a.reverse() # print(a) # ['5', '3', '2', '4', '1'] #sort(self, *args, **kwargs) 排序，默认升序，和reverse()配合使用, 也可以降序 # a = ['1','4','2','3','5'] # a.sort() # print(a) # ['1', '2', '3', '4', '5'] # a = ['1','4','2','3','5'] # a.sort() # a.reverse() # print(a) # ['5', '4', '3', '2', '1'] # a = ['1','4','2','3','5'] # a.sort(reverse=True) # print(a) # ['5', '4', '3', '2', '1'] ########################################################## #支持for、while循环 # a = ['1','2','3'] # for i in a: # print(i) # # #i = 0 # while i < len(a): # print(a[i]) # i += 1 #修改（替换元素） # test = ['a','b','c'] # test[1] = 0 # print(test) # ['a', 0, 'c'] #删除指定元素 # test = ['a','b','c'] # del test[2] # print(test) # ['a', 'b']