code: def parquet(self, path):
          
          if isinstance(path, basestring):
              return self._df(self._jreader.parquet(path))
          else:
              raise TypeError("path can be only a single string")
docs: Loads a Parquet file stream, returning the result as a :class:`DataFrame`.
  
          You can set the following Parquet-specific option(s) for reading Parquet files:
              * ``mergeSchema``: sets whether we should merge schemas collected from all \
                  Parquet part-files. This will override ``spark.sql.parquet.mergeSchema``. \
                  The default value is specified in ``spark.sql.parquet.mergeSchema``.
  
          .. note:: Evolving.
  
          >>> parquet_sdf = spark.readStream.schema(sdf_schema).parquet(tempfile.mkdtemp())
          >>> parquet_sdf.isStreaming
          True
          >>> parquet_sdf.schema == sdf_schema
          True