# -*- coding: utf8 -*-

from __future__ import absolute_import
from __future__ import division, print_function, unicode_literals

from itertools import chain
from .._compat import unicode_compatible
from ..utils import cached_property
from ._sentence import Sentence


@unicode_compatible
class Paragraph(object):
    def __init__(self, sentences):
        sentences = tuple(sentences)
        for sentence in sentences:
            if not isinstance(sentence, Sentence):
                raise TypeError("Only instances of class 'Sentence' are allowed.")

        self._sentences = sentences

    @cached_property
    def sentences(self):
        return tuple(s for s in self._sentences if not s.is_heading)

    @cached_property
    def headings(self):
        return tuple(s for s in self._sentences if s.is_heading)

    @cached_property
    def words(self):
        return tuple(chain(*(s.words for s in self._sentences)))

    def __unicode__(self):
        return "<Paragraph with %d headings & %d sentences>" % (
            len(self.headings),
            len(self.sentences),
        )

    def __repr__(self):
        return self.__str__()

# -*- coding: utf8 -*-

from __future__ import absolute_import
from __future__ import division, print_function, unicode_literals

from itertools import chain
from .._compat import unicode_compatible
from ..utils import cached_property
from ._sentence import Sentence


@unicode_compatible
class Paragraph(object):
    def __init__(self, sentences):
        for sentence in sentences:
            if not isinstance(sentence, Sentence):
                raise TypeError("Only instances of class 'Sentence' are allowed.")

        self._sentences = tuple(sentences)

    @cached_property
    def sentences(self):
        return tuple(s for s in self._sentences if not s.is_heading)

    @cached_property
    def headings(self):
        return tuple(s for s in self._sentences if s.is_heading)

    @cached_property
    def words(self):
        return tuple(chain(*(s.words for s in self._sentences)))

    def __unicode__(self):
        return "<Paragraph with %d headings & %d sentences>" % (
            len(self.headings),
            len(self.sentences),
        )

    def __repr__(self):
        return self.__str__()

--- 
+++ 
@@ -12,11 +12,12 @@
 @unicode_compatible
 class Paragraph(object):
     def __init__(self, sentences):
+        sentences = tuple(sentences)
         for sentence in sentences:
             if not isinstance(sentence, Sentence):
                 raise TypeError("Only instances of class 'Sentence' are allowed.")
 
-        self._sentences = tuple(sentences)
+        self._sentences = sentences
 
     @cached_property
     def sentences(self):
Allow using iterable of sentences in 'Paragraph'
