short python script to print the origin (branch and rev) of an SVN branch

svn-origin.py

#!/usr/bin/env python

# show the revision and stem from which a branch originates
# requires the 'lxml' and 'envoy' libraries

import sys
from lxml import etree
import envoy
import argparse

parser = argparse.ArgumentParser(
        description='Show origin (stem and revision) of a SVN branch')
parser.add_argument('svn_path', action='store', default='.', nargs='?')
parser.add_argument('--pretty', action="store_true", dest='pretty',
        default=False)

parsed = parser.parse_args()

c = envoy.run('svn log -v --xml --stop-on-copy {}'.format(parsed.svn_path))

try:
    tree = etree.XML(c.std_out)
except etree.XMLSyntaxError:
    print "couldn't parse output from svn"
    sys.exit(1)

# get the last log entry
r = tree.xpath('/log/logentry[last()]/paths/path')[0]
stem = r.get("copyfrom-path")
rev = r.get("copyfrom-rev")

if parsed.pretty:
    print "stemmed from '{}' at r{}".format(stem, rev)
else:
    print "{}@{}".format(stem, rev)