TypeError：＆＃x27; abcmeta＆＃x27;在运行Pyspark的Pagerank时，对象是不可订阅的

Question

我正在尝试运行 >实施页面排名。这是代码的一部分：

import re
import sys
from operator import add
from typing import Iterable, Tuple

from pyspark.resultiterable import ResultIterable
from pyspark.sql import SparkSession


def computeContribs(urls: ResultIterable[str], rank: float) -> Iterable[Tuple[str, float]]:
    """Calculates URL contributions to the rank of other URLs."""
    num_urls = len(urls)
    for url in urls:
        yield (url, rank / num_urls)


def parseNeighbors(urls: str) -> Tuple[str, str]:
    """Parses a urls pair string into urls pair."""
    parts = re.split(r'\s+', urls)
    return parts[0], parts[1]

但是当我运行它时，我会得到这个错误：

10 from collections.abc import Mapping
     11 
---> 12 def computeContribs(urls: ResultIterable[str], rank: float) -> Iterable[Tuple[str, float]]:
     13     """Calculates URL contributions to the rank of other URLs."""
     14     num_urls = len(urls)

TypeError: 'ABCMeta' object is not subscriptable

我该怎么办？我不知道为什么在定义函数时应该定义类型。