code: def requirements_from_file(filename, builder=None, interpreter=None):
    
  
    relpath = os.path.dirname(filename)
    with open(filename, 'r') as fp:
      return requirements_from_lines(fp.readlines(),
                                     builder=builder,
                                     relpath=relpath,
                                     interpreter=interpreter)
docs: Return a list of :class:`Resolvable` objects from a requirements.txt file.
  
    :param filename: The filename of the requirements.txt
    :keyword builder: (optional) The ResolverOptionsBuilder from which we should inherit
      default resolver options.
    :type builder: :class:`ResolverOptionsBuilder`