列表、字典的增删改查

一、列表:

# 列表的作用:存多个值,可以修改
# hobby = ['play','eat','sleep']
#
# 列表的具体操作
# 查看:
# hobby = ['play','eat','sleep',['egon','ysb']]
# f = hobby[2]  # 查看hobbyt列表内第二个元素
# print(f)
#
# 增加(1):
# hobby = ['play','eat','sleep',['egon','ysb']]
# hobby.append(元素)
# f = hobby.append('chenyang')
# print(f)
#
# 增加(2)
# hobby = ['play','eat','sleep',['egon','ysb']]
# hobby.insert(0,amy)
# print(hobby)
#
# 删除(1):
# hobby = ['play','eat','sleep',['egon','ysb']]
# X = hobby.pop(1)    #1为需要删除的字符,pop元素可以弹出需要删除的元素
# print(x)
# print(hobby)
#
# 删除(2):
# hobby = ['play','eat','sleep',['egon','ysb']]
# X = hobby.remove(1)    #1为需要删除的字符,remove为直接删除,无法保留
# print(x)
# print(hobby)
#
# 改:
# hobby = ['play','eat','sleep',['egon','ysb']]
# hobby[0]=1    #0代表列表内的索引,1为需要更改的字符
# print(hobby)
#

二、字典

#
# 字典的作用:key是唯一的,可以存储多个值
# 字典的具体操作
# 查:
# dic1 = {'name':'chenyang','age':38,'sex':'male'}
# f = dic1['name']  # 查看hobbyt列表内第一个元素,通过key查找到value
# print(f)
#
# 取:通过key找到value。
# dic1 = {'name':'chenyang','age':38,'sex':'male'}
# print(dic1.get('name',None))    #通过key取到value,如果找不到则返回None
#
# 存:字典内有相应的key就覆盖原来的value,反之新增key、value
# dic1 = {'name':'chenyang','age':38,'sex':'male'}
# dic1['sex'] = 'female'
# dic1['hobby'] = 'male'
# print(dic1)
#
# 改:
# dic1 = {'name':'chenyang','age':38,'sex':'male'}
# dic1.update({'hobby':male,'sex':'female'})
# print(dic1)
#
# 长度:计算字典内所有字典的长度
# dic1 = {'name':'chenyang','age':38,'sex':'male'}
# print(len(dic1))
#
# 包含:查找字典内的key
# dic1 = {'name':'chenyang','age':38,'sex':'male'}
# print('name' in dic1)
#
# 输出所有的key和value
# dic1 = {'name':'chenyang','age':38,'sex':'male'}
# print(dic1.items)
#  for k in dic1:
#       print(k,dic1[k])
#      print(k)
#
# 方法2
# for k in dic1:
# print(k,dic1[k])
#
# 输出所有的key
# dic1 = {'name':'chenyang','age':38,'sex':'male'}
# print(dic1.key)
#
# 输出所有的value
# dic1 = {'name':'chenyang','age':38,'sex':'male'}
# print(dic1.value)
原文地址:https://www.cnblogs.com/bingpan/p/7258904.html