Parsing srt subtitles

Question

Hi,

I want to parse srt subtitles:

    1
    00:00:12,815 --> 00:00:14,509
    Chlapi, jak to jde s
    těma pracovníma světlama?.

    2
    00:00:14,815 --> 00:00:16,498
    Trochu je zesilujeme.

    3
    00:00:16,934 --> 00:00:17,814
    Jo, sleduj.

Every item into structure. With this regexs:

A:

RE_ITEM = re.compile(r'(?P<index>\d+).'
    r'(?P<start>\d{2}:\d{2}:\d{2},\d{3}) --> '
    r'(?P<end>\d{2}:\d{2}:\d{2},\d{3}).'
    r'(?P<text>.*?)', re.DOTALL)

B:

RE_ITEM = re.compile(r'(?P<index>\d+).'
    r'(?P<start>\d{2}:\d{2}:\d{2},\d{3}) --> '
    r'(?P<end>\d{2}:\d{2}:\d{2},\d{3}).'
    r'(?P<text>.*)', re.DOTALL)

And this code:

    for i in Subtitles.RE_ITEM.finditer(text):
    result.append((i.group('index'), i.group('start'), 
             i.group('end'), i.group('text')))

With code B I have only one item in array (because of greedy .*) and with code A I have empty 'text' because of no-greedy .*?

How to cure this?

Thanks

Answer 1

Here's some code I had lying around to parse SRT files:

from __future__ import division

import datetime

class Srt_entry(object):
    def __init__(self, lines):
        def parsetime(string):
            hours, minutes, seconds = string.split(u':')
            hours = int(hours)
            minutes = int(minutes)
            seconds = float(u'.'.join(seconds.split(u',')))
            return datetime.timedelta(0, seconds, 0, 0, minutes, hours)
        self.index = int(lines[0])
        start, arrow, end = lines[1].split()
        self.start = parsetime(start)
        if arrow != u"-->":
            raise ValueError
        self.end = parsetime(end)
        self.lines = lines[2:]
        if not self.lines[-1]:
            del self.lines[-1]
    def __unicode__(self):
        def delta_to_string(d):
            hours = (d.days * 24) \
                    + (d.seconds // (60 * 60))
            minutes = (d.seconds // 60) % 60
            seconds = d.seconds % 60 + d.microseconds / 1000000
            return u','.join((u"%02d:%02d:%06.3f"
                              % (hours, minutes, seconds)).split(u'.'))
        return (unicode(self.index) + u'\n'
                + delta_to_string(self.start)
                + ' --> '
                + delta_to_string(self.end) + u'\n'
                + u''.join(self.lines))


srt_file = open("foo.srt")
entries = []
entry = []
for line in srt_file:
    if options.decode:
        line = line.decode(options.decode)
    if line == u'\n':
        entries.append(Srt_entry(entry))
        entry = []
    else:
        entry.append(line)
srt_file.close()

Answer 2

Why not use pysrt?

Answer 3

The text is followed by an empty line, or the end of file. So you can use:

r' .... (?P<text>.*?)(\n\n|$)'

Answer 4

splits = [s.strip() for s in re.split(r'\n\s*\n', text) if s.strip()]
regex = re.compile(r'''(?P<index>\d+).*?(?P<start>\d{2}:\d{2}:\d{2},\d{3}) --> (?P<end>\d{2}:\d{2}:\d{2},\d{3})\s*.*?\s*(?P<text>.*)''', re.DOTALL)
for s in splits:
    r = regex.search(s)
    print r.groups()