1. 字典是python中唯一的映射類型,字典的對象是可變的,一個字典中可以使用不同類型的鍵值。
2.字典的每個鍵值(key=value)對用冒號分割(:),每個隊用逗號分割,整個字典包括在大括號裏{}裏。
dic = {}
print (type(dic))
<type 'dict'>
dic1 = {'a':123,6:888}
print (dic1)
{'a': 123, 6: 888}
dic = {"a":123,'b':'hello'}
print (dic[('b')])
>>hello
dic = {"a":123,'b':'hello'}
dic[("a")] = "python"
print ( dic[('a')] )
dic = {"a":123,'b':'hello'}
dic[("a")] = "python"
print (dic.get('a'))
dic = {"a":123,'b':'hello'}
dic[("a")] = "python"
print (dic.get('a'))
print(dic.items())
返回的是:>[('a', 'python'), ('b', 'hello')]
dic = {"a":123,'b':'hello'}
dic[("a")] = "python"
dic1 = dic.copy()
print (dic1)
dic = {"a":123,'b':'hello'}
dic.pop('a')
print(dic)
>{'b': 'hello'}
就刪除了‘a’的值dic = {"a":123,'b':'hello'}
dic1 = {1:231,2:"adnd"}
dic.update(dic1)
print (dic)
>>{'a': 123, 1: 231, 2: 'adnd', 'b': 'hello'}
dic = {"a":2,'b':3}
print(dic.fromkeys(("a",'b','c'),100))
>>{'a': 100, 'c': 100, 'b': 100}
如果沒有,默認是None
dic = {"a":2,'b':3}
print(dic.fromkeys("abc"))
>>{'a': None, 'c': None, 'b': None}