fix flake8 complaints

import tempfile

import itertools

import logging

from typing import Any, Dict, List, Iterator, Optional, Sequence, Tuple, Union

from typing import Any, Dict, List, Iterator, Optional, Sequence, Tuple

import numpy as np

import pandas as pd

        shard_num += 1

        yield df

def load_pickle_file(input_file: str) -> Any:

  """Load from single, possibly gzipped, pickle file.

    with open(input_file, "rb") as opened_file:

      return pickle.load(opened_file)

def load_pickle_files(input_files: List[str]) -> Iterator[Any]:

  """Load dataset from pickle files.