Data type of dict

dic (dictionary)

Is a key-value dictionary of the type of data stored, the form: { 'name': 'Bob'}. No order in the low version, version 3.6 or more sequential.

Dictionary key must be immutable data types (such as strings, numbers), may be any type of value.

# Define and outputs a dictionary 
DIC = {
     ' name ' : ' Bob ' ,
     ' Age ' : 20 is ,
     ' height ' : 180 [ ,
     ' Sex ' : ' MALE ' 
} 
Print (DIC)

Dictionary common operation method

Increase of dictionary elements

• A dictionary name [ 'to increase the element name'] = "value of the element to be added, such as dic [" name "] = 'Bob'
• With setdefault () method, if the element does not exist, create

= DIC {
     ' name ' : ' Bob ' ,
     ' Age ' : 20 is ,
     ' Sex ' : ' MALE ' 
} 
DIC [ ' height ' ] = 180 [   # weight element does not exist, creating a new element 
dic.setdefault ( " weight " 123) # calls setdefault method of adding elements to 
Print (dic)

Delete dictionary elements

• pop () method, in accordance with the delete key elements, you can set parameters to avoid being given element can not be found
• popitem (), delete a random element in the old version, there are 3.6 or higher in order dictionary, delete the last element
• del dic [ "key"] delete key element in the manner of. del dic delete an entire dictionary
• clear () empty dictionary

dic={
    'name':'小明',
    'age':20,
    'sex':'male',
    "weight":123,
    1:2
}
dic.pop('name',None)
dic.popitem()
del dic['weight']
# dic.clear()
# del dic
print(dic)

Change the elements in the dictionary

• The copy operation again by means of the key
• dic1.update (dic2) Method j DIC2 the elements added to dic1, if dic1 already present in the element changes its value, there is added

dic1={
    'name':'小明',
    'age':20,
    'sex':'male',
    "weight":123,
    1:2
}
dic2={'name':'小明','height':180}
dic1.update(dic2)
print(dic1)

Find the elements in the dictionary

• dic.keys () Gets save all keys to the list
• dic.values ​​() Gets all the values ​​stored as a list
• dic.items () Gets all key-value pairs in the form of tuples stored in the list

dic={
    'name':'小明',
    'age':20,
    'sex':'male',
    "weight":123,
    1:2
}
print(dic.keys())
print(dic.values())
print(dic.items())

With a loop through the dictionary for get it is key

dic={
    'name':'小明',
    'age':20,
    'sex':'male',
    "weight":123,
    1:2
}
for i in dic:
    print(i)