io.py 文件源码

def combine_dataframe_into_pickle_file(dataframe, outfile, overwrite=False):
  """
  Save the provided pandas dataframe as a pickle to the provided file path. If a file is already present at that
  location, unpickle it, combine the dataframes, and save the result as a pickle (overwriting the file but keeping the
  data). Uses combine_first, prioritizing new data but keeping data from before.
  Obviously this will blow up catastrophically if there is a file at outfile which is not a DataFrame, and the data
  will get super gross if it *is* a DataFrame but the indices do not match.
  :param pandas.DataFrame dataframe: input dataframe
  :param str outfile: output file
  :return None:
  """
  if os.path.exists(outfile) and not overwrite:
    target_df = pandas.read_pickle(outfile)
    merged_df = dataframe.combine_first(target_df)
    merged_df.to_pickle(outfile)
  else:
    dataframe.to_pickle(outfile)