> import pymongo
> client=pymongo.MongoClient ('localhost',27017)
> db=client.students
> db.collection_names()
['students']
> students=db.students
> students.find()
<pymongo.cursor.Cursor object at 0x0000017A74305FD0>
> for item in students.find():
  print(item)
{'_id': ObjectId('59394a87ae09c56bd9c1d375'), 'name': 'zhangsan', 'age': 18.0, 'sex': 'male'}
> wangwu={'name':'wangwu','age':20,'sex':'male'}
> students.insert(wangwu)
ObjectId('593a7c5fedb5a1abeb757052')
> for item in students.find({'name':'wangwu'}):
  print(item)
{'_id': ObjectId('593a7c5fedb5a1abeb757052'), 'name': 'wangwu', 'age': 20, 'sex': 'male'}
> students.find_one()
{'_id': ObjectId('59394a87ae09c56bd9c1d375'), 'name': 'zhangsan', 'age': 18.0, 'sex': 'male'}
> students.find_one({'name':'wangwu'})
{'_id': ObjectId('593a7c5fedb5a1abeb757052'), 'name': 'wangwu', 'age': 20, 'sex': 'male'}
> students.find().count()
2
> students.remove({'name':'wangwu'})
{'ok': 1, 'n': 1}
> for item in students.find():
  print(item)
{'_id': ObjectId('59394a87ae09c56bd9c1d375'), 'name': 'zhangsan', 'age': 18.0, 'sex': 'male'}
> students.find().count()
1
> students.create_index([('name',pymongo.ASCENDING)])
'name_1'
> students.update({'name':'zhangsan'},{'$set':{'age':25}})
{'ok': 1, 'nModified': 1, 'n': 1, 'updatedExisting': True}
> students.find_one()
{'_id': ObjectId('59394a87ae09c56bd9c1d375'), 'name': 'zhangsan', 'age': 25, 'sex': 'male'}
> students.update({'age':25},{'$set':{'sex':'Female'}})
{'ok': 1, 'nModified': 1, 'n': 1, 'updatedExisting': True}
> students.remove()
{'ok': 1, 'n': 1}
> students.find().count()
0
> zhangsan={'name':'zhangsan','age':25,'sex':'Male'}
> lisi={'name':'lisi','age':21,'sex':'Male'}
> wangwu={'name':'wangwu','age':22,'sex':'Female'}
> students.insert_many([zhangsan,lisi,wangwu])
<pymongo.results.InsertManyResult object at 0x0000017A749FC5E8>
> for item in students.find().sort('name',pymongo.ASCENDING):
  print(item)
{'_id': ObjectId('593a806bedb5a1abeb757054'), 'name': 'lisi', 'age': 21, 'sex': 'Male'}
{'_id': ObjectId('593a806bedb5a1abeb757055'), 'name': 'wangwu', 'age': 22, 'sex': 'Female'}
{'_id': ObjectId('593a806bedb5a1abeb757053'), 'name': 'zhangsan', 'age': 25, 'sex': 'Male'}
> for item in students.find().sort([('sex',pymongo.DESCENDING),('name',pymongo.ASCENDING)]):
  print(item)
{'_id': ObjectId('593a806bedb5a1abeb757054'), 'name': 'lisi', 'age': 21, 'sex': 'Male'}
{'_id': ObjectId('593a806bedb5a1abeb757053'), 'name': 'zhangsan', 'age': 25, 'sex': 'Male'}
{'_id': ObjectId('593a806bedb5a1abeb757055'), 'name': 'wangwu', 'age': 22, 'sex': 'Female'}
>