| Server IP : 127.0.0.2 / Your IP : 3.15.2.88 Web Server : Apache/2.4.18 (Ubuntu) System : User : www-data ( ) PHP Version : 7.0.33-0ubuntu0.16.04.16 Disable Function : disk_free_space,disk_total_space,diskfreespace,dl,exec,fpaththru,getmyuid,getmypid,highlight_file,ignore_user_abord,leak,listen,link,opcache_get_configuration,opcache_get_status,passthru,pcntl_alarm,pcntl_fork,pcntl_waitpid,pcntl_wait,pcntl_wifexited,pcntl_wifstopped,pcntl_wifsignaled,pcntl_wexitstatus,pcntl_wtermsig,pcntl_wstopsig,pcntl_signal,pcntl_signal_dispatch,pcntl_get_last_error,pcntl_strerror,pcntl_sigprocmask,pcntl_sigwaitinfo,pcntl_sigtimedwait,pcntl_exec,pcntl_getpriority,pcntl_setpriority,php_uname,phpinfo,posix_ctermid,posix_getcwd,posix_getegid,posix_geteuid,posix_getgid,posix_getgrgid,posix_getgrnam,posix_getgroups,posix_getlogin,posix_getpgid,posix_getpgrp,posix_getpid,posix,_getppid,posix_getpwnam,posix_getpwuid,posix_getrlimit,posix_getsid,posix_getuid,posix_isatty,posix_kill,posix_mkfifo,posix_setegid,posix_seteuid,posix_setgid,posix_setpgid,posix_setsid,posix_setuid,posix_times,posix_ttyname,posix_uname,pclose,popen,proc_open,proc_close,proc_get_status,proc_nice,proc_terminate,shell_exec,source,show_source,system,virtual MySQL : OFF | cURL : ON | WGET : ON | Perl : ON | Python : ON | Sudo : ON | Pkexec : ON Directory : /usr/lib/python2.7/dist-packages/stdnum/ |
Upload File : |
# luhn.py - functions for performing the Luhn and Luhn mod N algorithms
#
# Copyright (C) 2010, 2011, 2012, 2013 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
"""The Luhn and Luhn mod N algorithms.
The Luhn algorithm is used to detect most accidental errors in various
identification numbers.
>>> validate('7894')
Traceback (most recent call last):
...
InvalidChecksum: ...
>>> checksum('7894')
6
>>> calc_check_digit('7894')
'9'
>>> validate('78949')
'78949'
An alternative alphabet can be provided to use the Luhn mod N algorithm.
The default alphabet is '0123456789'.
>>> validate('1234', alphabet='0123456789abcdef')
Traceback (most recent call last):
...
InvalidChecksum: ...
>>> checksum('1234', alphabet='0123456789abcdef')
14
"""
from stdnum.exceptions import *
def checksum(number, alphabet='0123456789'):
"""Calculate the Luhn checksum over the provided number. The checksum
is returned as an int. Valid numbers should have a checksum of 0."""
n = len(alphabet)
number = tuple(alphabet.index(i)
for i in reversed(str(number)))
return (sum(number[::2]) +
sum(sum(divmod(i * 2, n))
for i in number[1::2])) % n
def validate(number, alphabet='0123456789'):
"""Checks to see if the number provided passes the Luhn checksum."""
if not bool(number):
raise InvalidFormat()
try:
valid = checksum(number, alphabet) == 0
except Exception:
raise InvalidFormat()
if not valid:
raise InvalidChecksum()
return number
def is_valid(number, alphabet='0123456789'):
"""Checks to see if the number provided passes the Luhn checksum."""
try:
return bool(validate(number, alphabet))
except ValidationError:
return False
def calc_check_digit(number, alphabet='0123456789'):
"""With the provided number, calculate the extra digit that should be
appended to make it pass the Luhn checksum."""
ck = checksum(str(number) + alphabet[0], alphabet)
return alphabet[-ck]