def parse_file_size(s):
    """Return int from file size (1234, 55G, 1.7T)."""
    if not s:
        return int(s)  # will raise
    suffix = s[-1]
    power = 1000
    try:
        factor = {
            'K': power,
            'M': power**2,
            'G': power**3,
            'T': power**4,
            'P': power**5,
        }[suffix]
        s = s[:-1]
    except KeyError:
        factor = 1
    return int(float(s) * factor)