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| author | Sharoon Thomas <sharoon.thomas@openlabs.co.in> | 2014-03-18 16:39:01 +0100 |
|---|---|---|
| committer | Arthur de Jong <arthur@arthurdejong.org> | 2014-03-18 21:26:25 +0100 |
| commit | 85dd6f26be85f33986c2cd25c5a10cfdf4a5306c (patch) | |
| tree | 961bda84446bede59109a9d1477f2814b05f7b5a /stdnum/iso6346.py | |
| parent | 2405c89652607261587cfd619c723c805c2cf852 (diff) | |
Add support for ISO6346
Add validation and creation of check digit for ISO6346 codes.
See: https://github.com/arthurdejong/python-stdnum/pull/9
Diffstat (limited to 'stdnum/iso6346.py')
| -rw-r--r-- | stdnum/iso6346.py | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/stdnum/iso6346.py b/stdnum/iso6346.py new file mode 100644 index 0000000..07d1a85 --- /dev/null +++ b/stdnum/iso6346.py @@ -0,0 +1,84 @@ +# iso6346.py - functions for handling ISO 6346 +# +# Copyright (C) 2014 Openlabs Technologies & Consulting (P) Limited +# Copyright (C) 2014 Arthur de Jong +# +# This library is free software; you can redistribute it and/or +# modify it under the terms of the GNU Lesser General Public +# License as published by the Free Software Foundation; either +# version 2.1 of the License, or (at your option) any later version. +# +# This library is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +# Lesser General Public License for more details. +# +# You should have received a copy of the GNU Lesser General Public +# License along with this library; if not, write to the Free Software +# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA +# 02110-1301 USA + +"""ISO 6346 (International standard for container identification) + +ISO 6346 is an international standard covering the coding, identification and +marking of intermodal (shipping) containers used within containerized +intermodal freight transport. The standard establishes a visual identification +system for every container that includes a unique serial number (with check +digit), the owner, a country code, a size, type and equipment category as well +as any operational marks. The standard is managed by the International +Container Bureau (BIC). + +>>> validate('csqu3054383') +'CSQU3054383' +>>> validate('CSQU3054384') +Traceback (most recent call last): + ... +InvalidChecksum: ... +""" + +import re +import string + +from stdnum.exceptions import InvalidChecksum, InvalidFormat, InvalidLength, \ + ValidationError +from stdnum.util import clean + + +_iso6346_re = re.compile('^\w{3}(U|J|Z|R)\d{7}$') + + +def compact(number): + """Convert the number to the minimal representation. This strips the + number of any valid separators and removes surrounding whitespace.""" + return clean(number).strip().upper() + + +def calc_check_digit(number): + """Calculate check digit and return it for the 10 digit owner code and + serial number.""" + number = compact(number) + alphabet = '0123456789A BCDEFGHIJK LMNOPQRSTU VWXYZ' + return str(sum( + alphabet.index(n) * pow(2, i) + for i, n in enumerate(number)) % 11) + + +def validate(number): + """Validate the given number (unicode) for conformity to ISO 6346.""" + number = compact(number) + if len(number) != 11: + raise InvalidLength() + if not _iso6346_re.match(number): + raise InvalidFormat() + if calc_check_digit(number[:-1]) != number[-1]: + raise InvalidChecksum() + return number + + +def is_valid(number): + """Check whether the number conforms to the standard ISO6346. Unlike + the validate function, this will not raise ValidationError(s).""" + try: + return bool(validate(number)) + except ValidationError: + return False |