Find and replace IPv4 addresses in python.

fixipv4s.py

#!/usr/bin/env python
'''
Find all IPv4 addresses on a line and replace the interesting
ones.

Interesting IP addresses are those that are not in the exclude
list.
'''
# License: MIT Open Source
# Copyright (c) 2018 by Joe Linoff
from __future__ import print_function
import re
import sys

OCTET = r'(?:25[0-5]|2[0-4]\d|[01]?\d\d?)'
PATTERN = re.compile(r'\b(?:{octet}\.){{3}}{octet}\b'.format(octet=OCTET))

#PATTERN = re.compile(r'''
#\b
#(?:(?:25[0-5]|2[0-4]\d|[01]?\d\d?)\.){3}
#(?:25[0-5]|2[0-4]\d|[01]?\d\d?)
#\b
#''', re.VERBOSE)


def find(pattern, line):
    '''
    Return a generator will find all valid IPv4 addresses on the line.
    '''
    return (mip for mip in pattern.findall(line))


def fix(pattern, line, replace, xips):
    '''
    Fix a line by replacing all matching IP addresses on the
    line with specified replacement.
    '''
    for mip in find(pattern, line):
        if not xips or mip not in xips:
            line = re.sub(r'(?<![-\.\w\d])' + mip + r'(?![-\.\w\d])', replace, line)
    return line


def test():
    '''
    test
    '''
    verbose = False
    for opt in sys.argv:
        if opt in ['-v', '--verbose']:
            verbose = True

    def comp(pattern, replace, line, match, xips=None):
        '''
        Compare the results of the fix operation and report.
        '''
        newline = fix(pattern, line, replace, xips)
        passed = newline == match
        if passed:
            if verbose:
                print('\033[32;1mPASSED:\033[0m "{}" {}'.format(replace, xips))
            else:
                print('\033[32;1mPASSED:\033[0m "{:<64}" "{}" {}'.format(line, replace, xips))
        else:
            print('\033[31;1mFAILED:\033[0m "{}" {}'.format(replace, xips))

        if verbose or not passed:
            print('\tinput    "{}"'.format(line))
            print('\toutput   "{}"'.format(newline))
            print('\texpected "{}"'.format(match))
            print('\tpattern  "{}"'.format(pattern.pattern))

    rep = 'a.b.c.d'

    comp(PATTERN, rep,
         '1.2.3',
         '1.2.3')
    comp(PATTERN, rep,
         '1.2.3.4',
         'a.b.c.d')
    comp(PATTERN, rep,
         '1.2.3.4 ',
         'a.b.c.d ')
    comp(PATTERN, rep,
         ' 1.2.3.4 ',
         ' a.b.c.d ')
    comp(PATTERN, rep,
         ' 1.2.3.4',
         ' a.b.c.d')
    comp(PATTERN, rep,
         '1.2.3.4  5.6.7.8  9.0.1.2',
         'a.b.c.d  a.b.c.d  a.b.c.d')
    comp(PATTERN, rep,
         ' 1.2.3.4  5.6.7.8 ',
         ' a.b.c.d  a.b.c.d ')
    comp(PATTERN, rep,
         'x1.2.3.4',
         'x1.2.3.4')
    comp(PATTERN, rep,
         '1.2.3.4x',
         '1.2.3.4x')
    comp(PATTERN, rep,
         '1.2.3.4.5',
         '1.2.3.4.5')
    comp(PATTERN, rep,
         '1.2.3.4.5',
         '1.2.3.4.5')
    comp(PATTERN, rep,
         '1 1.2 1.2.3 1.2.3.4 1.2.3.4.5',
         '1 1.2 1.2.3 a.b.c.d 1.2.3.4.5')
    comp(PATTERN, rep,
         ' 100.200.300.400 ',
         ' 100.200.300.400 ')
    comp(PATTERN, rep,
         ' http://1.2.3.4:800/foo/bar ',
         ' http://a.b.c.d:800/foo/bar ')
    comp(PATTERN, rep,
         ' http://1.2.3.4:800/foo/bar http://127.0.0.1:8080 ',
         ' http://a.b.c.d:800/foo/bar http://127.0.0.1:8080 ',
         xips='127.0.0.1')


if __name__ == '__main__':
    test()