import csv


def read_file(filename, sep="\t"):
    """A helper function to read a file, and separate by the tab delimiter"""
    with open(filename, "r") as fd:
        lines = fd.readlines()
    lines = []
    with open(filename, newline="") as fd:
        reader = csv.reader(fd, delimiter=sep)
        for entry in reader:
            lines.append([e.strip() for e in entry])
    return lines