def return_student_assignment(df, student, assignment, assign_id, stu_id):
    """Return entries of selected student and assignment in dataframe."""
    if isinstance(student, list) & isinstance(assignment, list):
        return df[
            (df[stu_id].isin(student))
            & df[assign_id].isin(assignment)
        ]
    elif isinstance(student, str) & isinstance(assignment, str):
        return df[
            (df[stu_id] == student) & (df[assign_id] == assignment)
        ]
    else:
        raise TypeError(f"{student} or {assignment} is not list or str type")