python -【mongo】 处理Ob

• 2020 年 1 月 7 日
• 筆記

ObjectID简介

mongo存储的数据在没有特别指定_id数据类型时，默认类型为ObjectID ‘_id’: ObjectId(‘55717c9eb2c983c127000000’)

ObjectId is a 12-byte BSON type, constructed using:

• a 4-byte value representing the seconds since the Unix epoch,
• a 3-byte machine identifier,
• a 2-byte process id, and
• a 3-byte counter, starting with a random value.

python处理方式

基本思路就是转换成时间对象 ,然后处理.

objectid – Tools for working with MongoDB ObjectIds  Tools for working with MongoDB ObjectIds.    class bson.objectid.ObjectId(oid=None)  Initialize a new ObjectId.

• 从ObjectID生成时间对象

from bson.objectid import ObjectId  a = ObjectId('55717c9eb2c983c127000000')  a.generation_time.timetuple()    In [29]: a.generation_time.timetuple()  Out[29]: time.struct_time(tm_year=2015, tm_mon=6, tm_mday=5, tm_hour=10, tm_min=40, tm_sec=30, tm_wday=4, tm_yday=156, tm_isdst=0)    #到了这种格式就可以随便处理了  In [30]: time.strftime("%Y-%m-%d %H:%M:%S",a.generation_time.timetuple())  Out[30]: '2015-06-05 10:40:30'

• 生成ObjectID

# 时间对象转换  >>> gen_time = datetime.datetime(2010, 1, 1)  >>> dummy_id = ObjectId.from_datetime(gen_time)    >>> ObjectId(b'foo-bar-quux')  ObjectId('666f6f2d6261722d71757578')  >>> ObjectId('0123456789ab0123456789ab')  ObjectId('0123456789ab0123456789ab')  >>>  >>> # A u-prefixed unicode literal:  >>> ObjectId(u'0123456789ab0123456789ab')  ObjectId('0123456789ab0123456789ab')