Python data type, python

Python data type, python

A dictionary is a common and heavyweight data type in python consisting of a pair of key: value.

1. key, keys, values

A dictionary is a common and heavyweight data type in python consisting of a pair of key: value. key, keys, valuesid_db = {'jboss': {'mycis ': '10. 88.130.38 ', 'EC': '10. 88.130.29 ', 'rds': '10. 88.130.25 '}, 'jetty': {'mycis ': '10. 88.130.37 ', 'EC': '10. 88.130.36 '} print (id_db) for key in id_db: # dictionary key print (key, id_db [key]) key_list = id_db.keys () # dictionary keys attribute value_list = id_db.values () # dictionary values attribute print (key_list) print (value_list) # running result: {'jbos': {'rds': '10. 88.130.25 ', 'EC': '10. 88.130.29 ', 'mycis': '10. 88.130.38 '}, 'jetty': {'EC': '10. 88.130.36 ', 'mycis': '10. 88.130.37 '} jboss {'rds': '10. 88.130.25 ', 'EC': '10. 88.130.29 ', 'mycis': '10. 88.130.38 '} jetty {'EC': '10. 88.130.36 ', 'mycis': '10. 88.130.37 '} dict_keys (['jboss', 'jetty']) dict_values ([{'rds': '10. 88.130.25 ', 'EC': '10. 88.130.29 ', 'mycis': '10. 88.130.38 '}, {'EC': '10. 88.130.36 ', 'mycis': '10. 88.130.37 '}])

2. dictionary query dir [index], dir. get [index]

Server_list = {'uat': {'jbos': 'fca-vm-uat-jbos', 'jetty ': 'fca-vm-uat-jetty '}, 'dev': {'jbos': 'fca-vm-dev-jbos', 'jetty ': 'fca-vm-dev-jetty'}, 'prod ': {'jbos': 'fca-vm-prod-jbos', 'jetty ': 'fca-vm-prod-jetty'} print (server_list) print ("first query method") print (server_list ['uat']) # if this does not exist, the program reports an error print ("second query method ") print (server_list.get ('test') # if such a key does not exist, None is returned. get () # Test Result: {'prod': {'jetty ': 'fca-vm-prod-jetty', 'jbos ': 'fca-vm-prod-jbos'}, 'dev': {'jetty ': 'fca-vm-dev-jetty', 'jbos ': 'fca-vm-dev-jbos'}, 'uat': {'jetty ': 'fca-vm-uat-jetty', 'jbos ': 'fca-vm-uat-jbos'} first query method {'jetty ': 'fca-vm-uat-jetty', 'jbos ': 'fca-vm-uat-jbos'} second query method None

3. Add/change elements to the dictionary. Directly index and assign values. If this key is available, change it. If this key is not available, increase it.

Server_list = {'uat': {'jbos': 'fca-vm-uat-jbos', 'jetty ': 'fca-vm-uat-jetty '}, 'dev': {'jbos': 'fca-vm-dev-jbos', 'jetty ': 'fca-vm-dev-jetty'}, 'prod ': {'jbos': 'fca-vm-prod-jbos', 'jetty ': 'fca-vm-prod-jetty'} print (server_list) # Add the dictionary element server_list ['test'] = {'jbos': 'fca-vm-test ',} server_list ['dev'] ['apache '] = 'dev-apache' # change the dictionary valueserver_list ['uat'] ['jbos'] = '10. 88.130.38 '{'dev': {'jbos': 'fca-vm-dev-jbos', 'jetty': 'fca-vm-dev-jetty '}, 'uat': {'jbos': 'fca-vm-uat-jbos', 'jetty ': 'fca-vm-uat-jetty'}, 'prod ': {'jbos': 'fca-vm-prod-jbos', 'jetty ': 'fca-vm-prod-jetty'} {'test': {'jbos ': 'fca-vm-test'}, 'dev': {'jbos': 'fca-vm-dev-jbos', 'jetty ': 'fca-vm-dev-jetty ', 'apache': 'dev-apache'}, 'uat': {'jbos': '10. 88.130.38 ', 'jetty': 'fca-vm-uat-jetty '}, 'prod': {'jbos': 'fca-vm-prod-jbos ', 'jetty ': 'fca-vm-prod-jetty'} # running result:

4. Delete dictionary elements: del, pop

Server_list = {'uat': {'jbos': 'fca-vm-uat-jbos', 'jetty ': 'fca-vm-uat-jetty '}, 'dev': {'jbos': 'fca-vm-dev-jbos', 'jetty ': 'fca-vm-dev-jetty'}, 'prod ': {'jbos': 'fca-vm-prod-jbos', 'jetty ': 'fca-vm-prod-jetty'} print (server_list) del server_list ['uat'] server_list ['dev']. pop ('jbos') print (server_list) # running result: {'prod': {'jetty ': 'fca-vm-prod-jetty', 'jbos ': 'fca-vm-prod-jbos'}, 'dev': {'jetty ': 'fca-vm-dev-jetty', 'jbos ': 'fca-vm-dev-jbos'}, 'uat': {'jetty ': 'fca-vm-uat-jetty', 'jbos ': 'fca-vm-uat-jbos' }}{ 'prod': {'jetty ': 'fca-vm-prod-jetty', 'jbos ': 'fca-vm-prod-jbos'}, 'dev': {'jetty ': 'fca-vm-dev-jetty '}}

5. update attributes of the dictionary

Dir1 = {'id': 6103241990, 'name': 'xiaoping', 'age': 26} dir2 = {'id': 6103241988, 'name': 'ruiping ', 'Sex ': 'Woman'} print (dir1) print (dir2) dir1.update (dir2) # If dir2 has a key in dir1, updatedir1 is retained. If no key exists, dir1print (dir1) is retained) print (dir2) # Run the result {'id': 6103241990, 'age': 26, 'name': 'xiaoping'} {'id': 6103241988, 'sex ': 'Woman ', 'name': 'ruiping'} {'id': 6103241988, 'age': 26, 'sex': 'Woman', 'name ': 'ruiping'} {'id': 6103241988, 'sex': 'Woman ', 'name': 'ruiping '}

Update

6. items converts dictionaries to lists. It is not recommended to use

>>> a  = {'name':'bianxiaoping', 'sex':'man'}>>> a.items()dict_items([('name', 'bianxiaoping'), ('sex', 'man')])>>>

7. setdefault (if key exit, return a [key], if not a [key] = 'not exist'

""" D.setdefault(k[,d]) -> D.get(k,d), also set D[k]=d if k not in D """

>>> a  = {'name':'bianxiaoping', 'sex':'man'}>>> a.setdefault('age')>>> a{'age': None, 'name': 'bianxiaoping', 'sex': 'man'}>>> a.setdefault('name')'bianxiaoping'>>> a.setdefault('job','Not exist')'Not exist'>>> a{'age': None, 'name': 'bianxiaoping', 'sex': 'man', 'job': 'Not exist'}

 

8. The contained relationship in the dictionary (only for the key)

>>> a  = {'name':'bianxiaoping', 'sex':'man'}>>> 'sex' in aTrue>>> 'age' in aFalse>>> 'man' in aFalse>>>