pymongo中的尾光標似乎已停止工作

Question

我已經成功地在Pymongo中使用可尾光標兩年了，但是突然之間，今天，我相同的代碼拋出了“意外關鍵字”錯誤：

幾周前我升級到3.0 Mongo，它仍然可以正常工作，但是也許新的pymongo版本現在與今天剛安裝新版本（3.0.1）的方式有所不同？ 以前是pymongo 2.6.3。 我的代碼：

cursor = refreq.find(tailable = True, await_data = True)
while cursor.alive:
    xxx

因此，基本上任何時候只要我想知道的東西都插入到refreq集合中，就無需輪詢。 過去工作正常。 最近安裝了Pymongo 3.0.1版（今天）。

試圖也放一個空的字典

cursor = refreq.find({}, tailable = True, await_data = True)

但仍然給出相同的錯誤。 有什么改變嗎？

這是完整的線程代碼，以供參考：

def handleRefRequests(db, refqueue):
    """ handles reference data requests. It's threaded. Needs the database id. 
    will create a capped collection and constantly poll it for new requests"""
    print("Dropping the reference requests collection")
    db.drop_collection("bbrefrequests")
    print("Recreating the reference requests collection")
    db.create_collection("bbrefrequests", capped = True, size = 100 * 1000000) # x * megabytes
    refreq = db.bbrefrequests
    # insert a dummy record otherwise exits immediately
    refreq.insert({"tickers":"test", "fields":"test", "overfields":"test", "overvalues":"test", "done": False})
    cursor = refreq.find({}, tailable = True, await_data = True)
    while cursor.alive:
        try:
            post = cursor.next()
            if ("tickers" in post) and ("fields" in post) and ("done" in post): # making sure request is well formed
                if post["tickers"] != "test":
                    refqueue.put(post)
        except StopIteration:
            time.sleep(0.1)
        if not runThreads:
            print("Exiting handleRefRequests thread")
            break

Answer 1

在pymongo 3.0中， find為此使用了cursor_type選項。 tailable和await_data參數已刪除。

所以應該是：

cursor = refreq.find(cursor_type = CursorType.TAILABLE_AWAIT)