如何删除 RethinkDB 中基于组的一组数据 with Python

Question

我有一个 table 的乐器，我想按 category 来拆分它们，计算它们的数量，如果 category 组大于一个数字，则删除其中的所有乐器那个小组。我目前的代码是：

from rethinkdb import RethinkDB
from faker import Faker
from faker_music import MusicProvider
from random import random
from time import sleep

fake = Faker()
fake.add_provider(MusicProvider)
r = RethinkDB()

r.connect( "localhost", 28015).repl()

try:
  r.db("test").table_drop("instruments").run()
except:
  pass

r.db("test").table_create("instruments").run()

def instrument()->dict:
  instrument = {"name":fake.music_instrument(),"category":fake.music_instrument_category()}
  return instrument

initial = [instrument() for _ in range(3)]
r.table("instruments").insert(initial).run()

while True:
  check = random()
  if check < 0.5 and check >0.25:
    r.table("instruments").insert(instrument()).run()

  if  check < 0.25:
    cursor = r.table("instruments").group("category").count().gt(3).filter.delete().run()

  sleep(1)

其中 r.table("instruments").group("category").count().gt(3).filter.delete().run() 不起作用，但表示我正在努力实现的目标。

Answer 1

好的，这有效：

from rethinkdb import RethinkDB
from faker import Faker
from faker_music import MusicProvider
from random import random
from time import sleep

fake = Faker()
fake.add_provider(MusicProvider)
r = RethinkDB()

conn = r.connect( "localhost", 28015)

try:
  r.db("test").table_drop("instruments").run(conn)
except:
  pass

r.db("test").table_create("instruments").run(conn)

def instrument()->dict:
  instrument = {"name":fake.music_instrument(),"category":fake.music_instrument_category()}
  return instrument

initial = [instrument() for _ in range(3)]
r.table("instruments").insert(initial).run(conn)


while True:
  check = random()
  if check < 0.5 and check >0.25:
    r.table("instruments").insert(instrument()).run(conn)
  counts ={}
  counts = dict(r.table("instruments").group("category").count().run(conn))

  to_rm =[]
  for category, count in counts.items():
    if count >2:
      r.table("instruments").filter( {"category":category}).delete().run(conn)

  sleep(1)

但我确信有更精简的功能解决方案，如果有人知道请评论。

如何删除 RethinkDB 中基于组的一组数据 with Python

How to delete a set of data based on group in RethinkDB with Python

python

rethinkdb

rethinkdb-python