hey @jenniferL, to have the same behaviour as your example you’ll need to create a dataset loading script (see docs 8) which defines the configuration (de-en in your example), along with the column names and types. once your script is ready, you should be able to do something like:
from datasets import load_dataset

dataset = load_dataset('PATH/TO/MY/SCRIPT.py', 'my_configuration', data_files={'train': 'my_train_file.txt', 'validation': 'my_validation_file.txt'})

tips:

you might need to hardcode data_files explicitly in your script to preserve the exact same signature you have for load_dataset in your example.
you might find this 13 script template a useful place to start from