python 列表
发布: 2019-10-22 21:22:11标签: python
python列表练习
01# python列表入门02ls = [1, 2, 3, 4, 5, 6]0304# 获取对应下标05print(ls[2])06print(ls[-1])0708# 获取长度09print(len(ls))1011# 切片: 包括起始位置,不包括结束位置,不影响原列表12print(ls[1:2])13print(ls[1:])1415# 复制列表16print(ls[:])1718# 第三个参数表示间隔19print(ls[1:5:2])2021# 列表累加22a = [1, 2, 3, 4]23b = [5, 6, 7, 8]24print(a + b)2526# 列表复制27print([1, 2, 3] * 3)2829# in 和 not in30print(1 in [1, 2, 3, 4])31print(1 not in [1, 2, 3, 4])3233# min max34a = [1, 2, 3, 4, 5, 6, 2]35print(min(a))36print(max(a))3738# index: 出现的下标39# count:出现的次数40print(a.index(3))41print(a.count(2))4243# 修改列表44ls = ls2 = [1, 2, 3, 4]45print(ls, ls2)46ls[0] = 047print(ls, ls2)4849# del 删除元素50ls = [1, 2, 3, 4]51del ls[2]52# del ls{::2}53# del ls[1:]54print(ls)5556# 切片赋值,必须传入序列,不可以是数字57ls = [1, 2, 3, 4]58ls[0:2] = 'ab'59print(ls)60ls = [1, 2, 3, 4]61# ls[0:2] = ['a', 'b', 'c', 'd'] # ['a', 'b', 3, 4]62ls[0:2] = 'a' # ['a', 3, 4]63print(ls)6465# 插入66ls = [1, 2, 3, 4]67ls[1:1] = '插入'68print(ls)6970# 类型转换71a = '1234'72print(list(a))7374# 最后拆入75ls = [0, 1, 2]76ls.append('a')77print(ls)78# axtend 相当于 +=7980# 插入(下标,元素)81ls = [0, 1, 2]82ls.insert(1, 'aa')83print(ls)8485# 清空86ls.clear()87print('清空', ls)8889# pop 删除返回删除元素90ls = [0, 1, 2]91ls.pop(1)92print(ls)9394# 删除,只删除第一个95ls = [1, 2, 2, 3, 4]96ls.remove(2)97print('remove: ', ls)9899# 反序100ls = [1, 2, 3, 4]101ls.reverse()102print('反序:', ls)103104# 排序 sort105ls = [1, 0, 2, 4]106# ls.sort() # 正序107ls.sort(reverse=True) # 倒序108print('sort', ls)109110111# while遍历列表112# ls = [0, 1, 2, 3]113# i = 0114# while i < len(ls):115# print(ls[i])116# i += 1117118119# for 循环120ls = ['a', 'b', 'c']121for i in ls:122 print(i)
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