class_docstr: Wrapper for the Python's mmap class so that it can be properly read in
  by Python's csv.reader class.
  
  Parameters
  ----------
  f : file object
      File object to be mapped onto memory. Must support the 'fileno'
      method or have an equivalent attribute
class_docstr_tok: ["Wrapper","for","the","Python","'s","mmap","class","so","that","it","can","be","properly","read","in","by","Python","'s","csv.reader","class",".","Parameters","--","--","--","--","--","f",":","file","object","File","object","to","be","mapped","onto","memory",".","Must","support","the","'fileno'","method","or","have","an","equivalent","attribute"]
code: def __next__(self):
      newline = self.mmap.readline()
  
      # readline returns bytes, not str, in Python 3,
      # but Python's CSV reader expects str, so convert
      # the output to str before continuing
      if compat.PY3:
          newline = compat.bytes_to_str(newline)
  
      # mmap doesn't raise if reading past the allocated
      # data but instead returns an empty string, so raise
      # if that is returned
      if newline == "":
          raise StopIteration
      return newline
  
imports: import codecs
  from contextlib import closing, contextmanager
  import csv
  import mmap
  import os
  import zipfile
  import pandas.compat
  from pandas.compat import BytesIO, StringIO, string_types, text_type
  from pandas.errors import AbstractMethodError, DtypeWarning, EmptyDataError, ParserError, ParserWarning
  from pandas.core.dtypes.common import is_file_like, is_number
  from pandas.io.formats.printing import pprint_thing
label_desc: Use image node_id 4 for calling the MMapWrapper obj's underlying member method code with example usage: obj.__next__() and returns: newline