Python Basics-Dictionary (dictionary)

1. Dictionary definition, key unique, value arbitrary

dic={key0:value0,key1:value1}

2. Output

print(dic[key0])>>:value0

3. Traversing a dictionary
3.1keys () traverse the key in the dictionary

dic={‘name‘:‘zhangsan‘,‘age‘:20}for k in dic.keys():    print(k)>>:nameage             

3.2values () traverse the value in the dictionary

dic={‘name‘:‘zhangsan‘,‘age‘:20}for v in dic.values():    print(v)>>:zhangsan20

3.3items () traversing the key,value in the dictionary

dic={‘name‘:‘zhangsan‘,‘age‘:20}for k,v in dic.items():    print(k+‘:‘+str(v))>>:name:zhangsanage:20      

4. Dictionary Insert Element

dic={‘name‘:‘zhangsan‘,‘age‘:20}dic[‘job‘]=‘python‘print(dic)>>:{‘name‘: ‘zhangsan‘, ‘age‘: 20, ‘job‘: ‘python‘}

5. Modify values by key

dic={‘name‘:‘zhangsan‘,‘age‘:20}dic[‘name‘]=‘lisi‘print(dic)>>:{‘name‘: ‘lisi‘, ‘age‘: 20}

6.pop () Remove elements from the dictionary

dic={‘name‘:‘zhangsan‘,‘age‘:20}dic.pop(‘name‘)print(dic)>>:{‘age‘: 20}

7. Interpret whether the element is in the dictionary:

dic={‘name‘:‘zhangsan‘,‘age‘:20}tmp=‘name‘if tmp in dic:#和 if  tmp in dic.keys()相同:    print("%s in dic" %tmp)#判断元组是否在值中if tmp in dic.values():    print("%s in dic" %tmp)

Python Basics-Dictionary (dictionary)