load_jsonlines.py

import gzip
import jsonlines  # pip install jsonlines

def load_jsonlines(path):
    is_gzip = path[-2:] == 'gz'
    if is_gzip:
        with gzip.open(path, 'rb') as f:
            reader = jsonlines.Reader(f)
            for obj in reader:
                yield obj
    else:
        with jsonlines.open(path) as reader:
            for obj in reader:
                yield obj
                
data = load_jsonlines('path/to/file.jsonl.gz')

# `data` is a generator, so optionally cast to list to load it all into memory:
data = list(data)