1，创建字典
a，直接创建
dic = {‘a‘:1,‘b‘:2,‘c‘:3}
print (dic)
>>>{‘b‘: 2, ‘a‘: 1, ‘c‘: 3}
b，函数创建
dic= dict(a=1,b=2,c=3)
print (dic)
>>>{‘b‘: 2, ‘c‘: 3, ‘a‘: 1}
2，基本操作
a，判断
dic1 = {‘a‘:1,‘b‘:2,‘c‘:3}
print (‘a‘ in dic1) # 此处只能判断key
print (1 in dic1)
>>>True
False
b，追加
dic = {‘a‘:1,‘b‘:2,‘c‘:3}
dic[‘d‘] = 4
print (dic)
>>>{‘c‘: 3, ‘a‘: 1, ‘b‘: 2, ‘d‘: 4}
c，修改
dic = {‘a‘:1,‘b‘:2,‘c‘:3}
dic[‘a‘] = 4
print (dic)
>>>{‘c‘: 3, ‘a‘: 4, ‘b‘: 2}
d，删除
dic = {‘a‘:1,‘b‘:2,‘c‘:3}
del dic[‘a‘]
print (dic)
>>>{‘c‘: 3, ‘b‘: 2}
3，常用功能
a，追加
dic1 = {‘a‘:1,‘b‘:2,‘c‘:3}
dic2 = {‘d‘:4}
dic3 = dic2.update(dic1) # 将字典dic1合并到字典dic2中去
print (dic1)
print (dic2)
>>>{‘b‘: 2, ‘a‘: 1, ‘c‘: 3}
{‘d‘: 4, ‘a‘: 1, ‘b‘: 2, ‘c‘: 3}
c，复制
dic1 = {‘a‘:1,‘b‘:2,‘c‘:3}
dic2 = {‘d‘:4}
dic3 = dic1.copy()
dic1.update(dic2) # 注意不能将追加后的字典直接赋值给变量dic4=dic1.update(dic2)
print (dic3)
print (dic1)
d，清空
dic = {‘a‘:1,‘b‘:2,‘c‘:3}
dic.clear() # 清空字典
print (dic)
>>>{}
4，访问字典
a，获取健key对应值value
dic = {‘a‘:1,‘b‘:2,‘c‘:3}
print (dic.get(‘a‘))
>>>1
b，获取所有健key
dic = {‘a‘:1,‘b‘:2,‘c‘:3}
print (dic.keys())
>>>dict_keys([‘a‘, ‘b‘, ‘c‘])
c，获取所有值value
dic = {‘a‘:1,‘b‘:2,‘c‘:3}
print (dic.values()
>>>dict_values([1, 2, 3])
d，获取健值对items
dic = {‘a‘:1,‘b‘:2,‘c‘:3}
print (dic.items())
>>>dict_items([(‘a‘, 1), (‘b‘, 2), (‘c‘, 3)])
5，遍历字典
a，遍历所有健key
dic = {‘a‘:1,‘b‘:2,‘c‘:3}
for key in dic.keys():
print (key)
>>>b
a
c
b，遍历所有值values
dic = {‘a‘:1,‘b‘:2,‘c‘:3}
for value in dic.values():
print (value)
>>>2
1
3
c，遍历所有健值对items
dic = {‘a‘:1,‘b‘:2,‘c‘:3}
for (k,v) in dic.items():
print (k,v)
>>>a 1
b 2
c 3
原文：https://www.cnblogs.com/qianqicheng/p/10547907.html