diff options
Diffstat (limited to 'doc/source/index.rst')
| -rw-r--r-- | doc/source/index.rst | 62 |
1 files changed, 59 insertions, 3 deletions
diff --git a/doc/source/index.rst b/doc/source/index.rst index f6d3e38..81659ed 100644 --- a/doc/source/index.rst +++ b/doc/source/index.rst @@ -1787,7 +1787,6 @@ attributes, and delete attributes:: tag # <blockquote>Extremely bold</blockquote> - Modifying ``.string`` --------------------- @@ -2419,8 +2418,9 @@ as ``exclude_encodings``:: soup.original_encoding 'WINDOWS-1255' -(This isn't 100% correct, but Windows-1255 is a compatible superset of -ISO-8859-8, so it's close enough.) +Windows-1255 isn't 100% correct, but that encoding is a compatible +superset of ISO-8859-8, so it's close enough. (``exclude_encodings`` +is a new feature in Beautiful Soup 4.4.0.) In rare cases (usually when a UTF-8 document contains text written in a completely different encoding), the only way to get Unicode may be @@ -2609,6 +2609,62 @@ document is Windows-1252, and the document will come out looking like ``UnicodeDammit.detwingle()`` is new in Beautiful Soup 4.1.0. + +Comparing objects for equality +============================== + +Beautiful Soup says that two ``NavigableString`` or ``Tag`` objects +are equal when they represent the same HTML or XML markup. In this +example, the two <b> tags are treated as equal, even though they live +in different parts of the object tree, because they both look like +"<b>pizza</b>":: + + markup = "<p>I want <b>pizza</b> and more <b>pizza</b>!</p>" + soup = BeautifulSoup(markup, 'html.parser') + first_b, second_b = soup.find_all('b') + print first_b == second_b + # True + + print first_b.previous_element == second_b.previous_element + # False + +If you want to see whether two variables refer to exactly the same +object, use `is`:: + + print first_b is second_b + # False + +Copying Beautiful Soup objects +============================== + +You can use ``copy.copy()`` to create a copy of any ``Tag`` or +``NavigableString``:: + + import copy + p_copy = copy.copy(soup.p) + print p_copy + # <p>I want <b>pizza</b> and more <b>pizza</b>!</p> + +The copy is considered equal to the original, since it represents the +same markup as the original, but it's not the same object:: + + print soup.p == p_copy + # True + + print soup.p is p_copy + # False + +The only real difference is that the copy is completely detached from +the original Beautiful Soup object tree, just as if ``extract()`` had +been called on it:: + + print p_copy.parent + # None + +This is because two different ``Tag`` objects can't occupy the same +space at the same time. + + Parsing only part of a document =============================== |