字典的创建

字典的创建方式：
面试会考
方式一：

dic = dict((('one', 1), ('two', 2), ('three', 3)))
print(dic)  # {'one': 1, 'two': 2, 'three': 3}

方式二：

dic = dict(one=1, two=2, three=3)
print(dic)

方式三：

dic = dict({'one': 1, 'two': 2, 'three': 3})
print(dic)

方式四：

a = dict(zip(("a","b","c","d","e"),(1,2,3,4,5)))

 

 相关知识：

# update相关 ***
dic = {'name': '太白', 'age': 18}
dic.update(hobby='运动', hight='175')
dic.update(name='太白金星')
dic.update([(1, 'a'),(2, 'b'),(3, 'c'),(4, 'd')])  # 面试会考
#{'name': '太白金星', 'age': 18, 'hobby': '运动', 'hight': '175', 1: 'a', 2: 'b', 3: 'c', 4: 'd'}
print(dic)
dic1 = {"name":"jin","age":18,"sex":"male"}
dic2 = {"name":"alex","weight":75}
dic1.update(dic2)  # 更新，有则覆盖，无责添加
print(dic1)  # {'name': 'alex', 'age': 18, 'sex': 'male', 'weight': 75}
print(dic2)  #{"name":"alex","weight":75}

 

# fromkeys相关
dic = dict.fromkeys('abc', 100)
print(dic)   #{'a': 100, 'b': 100, 'c': 100}
dic = dict.fromkeys([1, 2, 3], 'alex')
print(dic)      #{1: 'alex', 2: 'alex', 3: 'alex'}
# 坑：值共有一个,面试题
dic = dict.fromkeys([1,2,3],[])
print(dic)  #{1: [], 2: [], 3: []}
dic[1].append(666)
print(dic)      #{1: [666], 2: [666], 3: [666]}

 

dic = dict.fromkeys('abc',[])
dic['a'].append(666)
dic['b'].append(111)
print(dic)  #{'a': [666, 111], 'b': [666, 111], 'c': [666, 111]}