import data_loading_utils.py

file_name = 'file_name.ext'
CHUNK_SIZE = 1000000 # configure this variable depending on your machine's hardware configuration

# callback method
def process_lines(data, eof, file_name):

    # check if end of file reached
    if not eof:
         # process data, data is one single line of the file

    else:
         # end of file reached

        
if __name__ == "__main__":
    data_loading_utils.read_lines_from_file_as_data_chunks(file_name, chunk_size=CHUNK_SIZE, callback=self.process_lines)

    # process_lines method is the callback method. 
    # It will be called for all the lines, with parameter data representing one single line of the file at a time