xdc_git_python_20210511/python_base/day4/字典高级操作.py

# -*- coding: UTF-8 -*-

###============更新字典============### 
# d1 = {}
# d1['a'] = 1
# d1['b'] = 2
# d1['li'] = [1,2,3]
# print(d1)
# d1['info'] = {'name':'xdc'}
# print(d1)
# d1['b'] = 200
# print(d1)
# print(    d1['li'][-1]       )
# print(    d1['info']['name']    )
###============将两个列表对应成一个字典============### 
# en = {'a', 'b'}
# nums = {1, 2}
# d2 = {}
# for x,y in zip(en,nums):
#     d2[x] = y
# print(d2)

# menus = ['get CPU', 'men']

# for idx, item in enumerate(menus,1):   ###自动增加索引值（以1开始）
#     print(idx, item)

# menu_dice = {}
# for idx,item in enumerate(menus,1):
#     menu_dice[str(idx)] = item
# print(menu_dice)
# for k,v in menu_dice.items():  #字典本身不是可迭代对象，items才是
#     print(k,v)
# print( )
# inp = input(">>:")
#print(menu_dice.get(inp))
###============获取字典Key对应的Value============###   
# dict_obj = {'a': '1','b':'2'}
# print(dict_obj.get('a')) # 获取到 a 对应的value
# print(dict_obj.get('c')) # key不存在于字典中，则返回None
# print(dict_obj.get('c','key不存在')) #key 不存在，返回指定的value
# getKey = dict_obj.get('c')
# print(type(getKey),getKey)

###============获取字典中所有的key和Value============### 
info_dict = {"name":"xdc","age":8848}
# d_keys = info_dict.keys()
# print(d_keys)
# print(list(d_keys))

print(info_dict.values())  # 这里与python2不一致
print(info_dict.items())   # 这里与python2不一致
for k,v in info_dict.items():
    print(k,v)

###============更新字典============### 

# d5 = {'a':1}
# d6 = {'b':2}
# d5.update(d6)
# print(d5)
# d5.update(c=3,d=10)
# print(d5)
# #更新时，相同的key会被新的值覆盖

# x = {'a':1, 'b':2}
# y = {'c':1, 'd':2}
# z = {**x,**y} # 合并字典操作（python 3.5+版本支持）
# print(z)

###============判断字典 key 与 Valye  ============### 
# x = {'a':1, 'b':2}
# print('a' in x.keys())
# print(2 in x.values())

###============删除字典与清空============###
# dict_obj = {'a':1}
# del dict_obj['a']
# print(id(dict_obj))
# dict_obj = {}
# print(id(dict_obj))
# dict_obj.clear()

# d6 = {'a':1,'b':2,'li':[1,2,3]}
# item = d6.pop('b') #从字典中删除指定key的键值对，并返回这个key对应对值
# print(item)

# d6 = {'a':1,'b':2,'li':[1,2,3]}
# item = d6.popitem() # 删除字典中的键值对，并返回这个键和值 （默认删除最后一个键值对）
# print(item)

###============字典可迭代对象============###
# en = ['a','b','c','d']
# nums = ['1','2','3','4']

# zip_obj = zip(en,nums)
# print(zip_obj)
# print(list(zip_obj))
# print(dict(zip_obj))

# l3 = [('a', '1'), ('b', '2'), ('c', '3'), ('d', '4')]
# for item in l3:
#     print(item)
#     w,n = item
#     print(w,n)
# for w,n in l3:
#     print(w,n)

# t3 = ('a1','b2')
# for w,n in t3:
#     # print(w,"->", n)
#     s = f"{w}-->{n}" 
#     print(s)