code: def load_train_file(config_file_path):
      
      from pylearn2.config import yaml_parse
  
      suffix_to_strip = '.yaml'
  
      # publish environment variables related to file name
      if config_file_path.endswith(suffix_to_strip):
          config_file_full_stem = config_file_path[0:-len(suffix_to_strip)]
      else:
          config_file_full_stem = config_file_path
  
      for varname in ["PYLEARN2_TRAIN_FILE_NAME", #this one is deprecated
              "PYLEARN2_TRAIN_FILE_FULL_STEM"]: #this is the new, accepted name
          environ.putenv(varname, config_file_full_stem)
  
      directory = config_file_path.split('/')[:-1]
      directory = '/'.join(directory)
      if directory != '':
          directory += '/'
      environ.putenv("PYLEARN2_TRAIN_DIR", directory)
      environ.putenv("PYLEARN2_TRAIN_BASE_NAME", config_file_path.split('/')[-1] )
      environ.putenv("PYLEARN2_TRAIN_FILE_STEM", config_file_full_stem.split('/')[-1] )
  
      return yaml_parse.load_path(config_file_path)
docs: Loads and parses a yaml file for a Train object.
      Publishes the relevant training environment variables