def zfill_scan(scan_list, fill_num):
    """Change int to str and fill them with the user set number of zeros

    Parameters
    ==========
    scan_list (str):
        a list string of the scans the user would like to import

    fill_num (int):
        the amount of numbers each number should have. fill_num=4 turns '40' into '0040'

    Returns
    =======
    A list of scan numbers with corrected zfill values
    """
    new_scan = []
    for scan in scan_list:
        new_scan.append(scan.zfill(fill_num))
    return new_scan
