判断集合是否已存在

#!/usr/bin/python3
 
import pymongo
 
myclient = pymongo.MongoClient('mongodb://localhost:27017/')
 
mydb = myclient['runoobdb']
 
collist = mydb. list_collection_names()
# collist = mydb.collection_names()
if "sites" in collist:   # 判断 sites 集合是否存在
  print("集合已存在！")