Function nti

Lib/tarfile.py:173–191

Convert a number field to a python number.

(s)

    return s.decode(encoding, errors)

def nti(s):
    """Convert a number field to a python number.
    """
    # There are two possible encodings for a number field, see
    # itn() below.
    if s[0] in (0o200, 0o377):
        n = 0
        for i in range(len(s) - 1):
            n <<= 8
            n += s[i + 1]
        if s[0] == 0o377:
            n = -(256 ** (len(s) - 1) - n)
    else:
        try:
            s = nts(s, "ascii", "strict")
            n = int(s.strip() or "0", 8)
        except ValueError:
            raise InvalidHeaderError("invalid header")
    return n

def itn(n, digits=8, format=DEFAULT_FORMAT):
    """Convert a python number to a number field.