test_smart_truncate.py

# -*- coding: utf-8 -*-
import pytest

def smart_struncate(s, length=100, suffix='…'):
    # Be smart here.
    return s

@pytest.mark.parametrize('given,expected,length,suffix', [
    [u'Ceci est une longue phrase qui pourrait éventuellement servir de titre à billet de blog mais est vraiment beaucoup trop longue',  # noqa
     u'Ceci est une longue phrase qui pourrait éventuellement servir de titre à billet de blog mais est…', None, None],  # noqa
    ['A short sentence', 'A short sentence', None, None],
    ['A short sentence', u'A short…', 10, None],
    ['A short sentence', u'A short.', 10, '.'],
    ['A short sentence', u'A short', 10, ''],
    [u"أكثر من خمسين لغة،", u"أكثر من خمسين لغة،", None, None],
    [u"أكثر من خمسين لغة،", u"أكثر…", 5, None],
    ["I'm 17 chars long", "I'm 17 chars long", 17, None],
    ["I've a space at 13", u"I've a space…", 13, None],
    ["I've a space at 13", u"I've a space…", 12, None],
    ["I've a space at 13", u"I've a space…", 14, None],
    ['Anticonstitutionnellement', u'Anticon…', 7, None],
    ["I've a comma, at 13", u"I've a comma…", 13, None],
])
def test_smart_struncate(given, expected, length, suffix):
    kwargs = {}
    if length is not None:
        kwargs['length'] = length
    if suffix is not None:
        kwargs['suffix'] = suffix
    assert smart_truncate(given, **kwargs) == expected

ulgy_smart_truncate.py

def smart_truncate(s, length=100, suffix=u'…'):
    if len(s) > length:
        s = s[:length+1]
        if ' ' in s:
            s = u' '.join(s.split(u' ')[0:-1])
        else:
            s = s[:-1]
        # We don't want to add a punctuation after another punctuation.
        while not s[-1].isalnum():
            s = s[:-1]
        s = s + suffix
    return s