python字典

#字典定义的基本形式：key:value
# d={'name':'egon','age':18} #d=dict({'name':'egon','age':18})
#
# print(id(d),type(d),d)
#定义字典需要注意的问题：key必须是不可变类型，或者说是可hash类型
# print(hash(1))
# print(hash('xxxxxx'))
# print(hash((1,2,3)))

# print(hash({'a':1}))

d={1:'id','a':1,'b':2,'name':'egon',(1,2):'aaaaaaaa'}

#字典的取值,字典是无序的
# print(d[1])
# print(d['name'])
# print(d[(1,2)])

# d={'name':'alex','age':18}
# print(d['name'])
# d['name']='aaaaasb'
# print(d)

#循环
d={'name':'alex','age':18,'sex':'male','height':130,'weight':200}
# print(d.keys())
# print(d.values())
# print(type(d.keys()))

# for k in d:
# print(k,d[k])

# l=[1,2,3]
# for i in l:
# print(i)

# t=(1,2,3)
# for i in t:
# print(i)

# s='hello'
# for i in s:
# print(i)

'''
一：可变不可变
可变：列表，字典
不可变：数字，字符串，元组

二：存放值的个数
一个值：数字，字符串
多个值(容器类型)：列表，元组，字典

三：取值方式
直接取值：数字
序列类型：字符串，元组，列表
映射类型：字典
'''

#字典的嵌套使用

# d={'a':1}
# print(d['b'])
# print(d.get('a'))

# user_info=[
# {'username':'egon','password':'123'},
# {'username':'alex','password':'alex3714'},
# {'username':'yuanhao','password':'sb123'},
# ]
# for item in user_info:
# print(item['username'],item['password'])

# tag=True
# while tag:
# user=input('u>>: ')
# pwd=input('p>>: ')
# for item in user_info:
# if user == item['username'] and pwd ==item['password']:
# print('login ok')
# tag=False
# break

# user_info=[
# {'username':'egon','password':'123'},
# {'username':'alex','password':'alex3714'},
# {'username':'yuanhao','password':'sb123'},
# ]

user_dic={
'egon':'123',
'alex':'alex3714',
'yuanhao':'sb123'
}
# print('egon' in user_dic)
while True:
user=input('u>>: ')
pwd=input('p>>: ')
if user in user_dic:
if pwd == user_dic[user]:
print('login ok')
break

# if user == 'egon' and pwd == '123':
# print('login ok')
# break