# 合法
dic = {123: 456, True: 999, "id": 1, "name": ‘sylar‘, "age": 18, "stu": [‘帅
哥‘, ‘美?‘], (1, 2, 3): ‘麻花藤‘}
print(dic[123])
print(dic[True])
print(dic[‘id‘])
print(dic[‘stu‘])
print(dic[(1, 2, 3)])
# 不合法
# dic = {[1, 2, 3]: ‘周杰伦‘} # list是可变的. 不能作为key
# dic = {{1: 2}: "哈哈哈"} # dict是可变的. 不能作为key
dic = {{1, 2, 3}: ‘呵呵呵‘} # set是可变的, 不能作为key

dic = {}
dic[‘name‘] = ‘周润发‘ # 如果dict中没有出现这个key, 就会新增?个key-value的组
合进dict
dic[‘age‘] = 18
print(dic)


# 如果dict中没有出现过这个key-value. 可以通过setdefault设置默认值
dic.setdefault(‘李嘉诚‘) # 也可以往??设置值.
dic.setdefault("李嘉诚", "房地产") # 如果dict中已经存在了. 那么setdefault将不会
起作?


print(dic)

ret = dic.pop("jay")
print(ret)


del dic["jay"]
print(dic)


# 随机删除.
ret = dic.popitem()


# 清空字典中的所有内容
dic.clear()

dic = {"id": 123, "name": ‘sylar‘, "age": 18}
dic1 = {"id": 456, "name": "麻花藤", "ok": "wtf"}
dic.update(dic1) # 把dic1中的内容更新到dic中. 如果key重名. 则修改替换. 如果不存在key, 则新增.
print(dic)
print(dic1)

print(dic[‘name‘])
# print(dic[‘sylar‘]) # 报错
print(dic.get("ok"))
print(dic.get("sylar")) # None
print(dic.get("sylar", "?B")) # ?B

dic = {"id": 123, "name": ‘sylar‘, "age": 18, "ok": "科?"}

print(dic.keys()) # dict_keys([‘id‘, ‘name‘, ‘age‘, ‘ok‘]) 不?管它是什么.当成list来?就?
for key in dic.keys():
　　 print(key)

print(dic.values()) # dict_values([123, ‘sylar‘, 18, ‘科?‘]) ?样. 也当
list来?
for value in dic.values():
　　 print(value)

print(dic.items()) # dict_items([(‘id‘, 123), (‘name‘, ‘sylar‘), (‘age‘,18), (‘ok‘, ‘科?‘)]) 这个东?也是list. 只不过list中装的是tuple
for key, value in dic.items(): # ?? 这个是解构
　　 print(key, value)

# 解构
a, b = 1, 2
print(a, b)

(c, d) = 3, 4
print(c, d)

e, f = [1, 2, 3] # 解构的时候注意数量必须匹配
print(e, f)

# 字典的嵌套
dic1 = {
　　 "name": "汪峰",
　　 "age": 18,
　　 "wife": {
　　 "name": ‘章?怡‘,
　　 "age": 28
　　 },
　　 "children": [‘第?个?孩?‘, ‘第?个?孩?‘],
　　 "desc": ‘峰哥不会告我吧. 没关系. 我想上头条的‘
}
print(dic1.get("wife").get("name"))
print(dic1.get("children"))
print(dic1.get("children")[1])

a = ‘alex‘
b = ‘alex‘
print(a == b)  # True

n = 10
n1 = 10
print(n == n1) # True

li1 = [1,2,3]
li2 = [1,2,3]
print(li1 == li2) True

a = ‘alex‘
print(id(a))   # 36942544  内存地址

n = 10
print(id(n))     #1408197120

li = [1,2,3]
print(id(li))      #38922760

#字符串
a = ‘alex‘
b = ‘alex‘
print(a is b)  #True
#数字
n = 10
n1 = 10
print(n is n1)   #True

#列表
li =[1,2,3]
li2 =[1,2,3]
print(li is li2)  #False
#元组
tu =(1,2,3)
tu1 =(1,2,3)
print(tu is tu1)   # False
#字典
dic1 = {‘name‘:‘alex‘}
dic = {‘name‘:‘alex‘}
print(dic1 is dic)    #False

n = -6
n1 = -6
print(n is n1)  #False

n = -5
n1 = -5
print(n is n1)    #True

n = 257
n1 = 257  # 在pycharm中会显示true，在终端中是false，因为pycharm会做出它认为是优化的方案，但是却打破了python的功能
print(n is n1)     #True

a = ‘alex@‘a1 = ‘alex@‘print(a is a1)    # Fales

a = ‘a‘*21b = ‘a‘*21print(a is b)    #False

a = ‘aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa‘b = ‘aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa‘print(a is b)    #True

s = ‘alex‘print(s.encode(‘utf-8‘))    # 编码 encode(‘utf-8‘) utf-8 是指定要编码成什么样的编码类型print(s1.decode(‘utf-8‘))   # 

s = ‘饿了‘s1 = s.encode(‘gbk‘)      #b‘饿了吗‘    #b‘\xe9\xa5\xbf\xe4\xba\x86\xe5\x90\x97‘print(s.encode(‘gbk‘))                 #b‘\xb6\xf6\xc1\xcb\xc2\xf0‘print(s1)print(s1.decode(‘utf-8‘))