I've just started tinkering with scrapy in conjunction with BeautifulSoup and I'm wondering if I'm missing something very obvious but I can't seem to figure out how to get the doctype of a returned html document from the resulting soup object.
Given the following html:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html lang="en">
<head>
<meta charset=utf-8 />
<meta name="viewport" content="width=620" />
<title>HTML5 Demos and Examples</title>
<link rel="stylesheet" href="/css/html5demos.css" type="text/css" />
<script src="js/h5utils.js"></script>
</head>
<body>
<p id="firstpara" align="center">This is paragraph <b>one</b>
<p id="secondpara" align="blah">This is paragraph <b>two</b>.
</html>
Can anyone tell me if there's a way of extracting the declared doctype from it using BeautifulSoup?
Beautiful Soup 4 has a class for DOCTYPE declarations, so you can use that to extract all the declarations at top level (though you're no doubt expecting one or none!)
def doctype(soup):
items = [item for item in soup.contents if isinstance(item, bs4.Doctype)]
return items[0] if items else None
You can go through top-level elements and check each to see whether it is a declaration. Then you can inspect it to find out what kind of declaration it is:
for child in soup.contents:
if isinstance(child, BS.Declaration):
declaration_type = child.string.split()[0]
if declaration_type.upper() == 'DOCTYPE':
declaration = child
You could just fetch the first item in soup contents:
>>> soup.contents[0]
u'DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd"'
Related
I want to use Python to parse HTML markup, and given one of the resultant DOM tree elements, get the start and end offsets of that element within the original, unmodified markup.
For example, given the HTML markup (with \n EOL chars)
<?xml version="1.0" encoding="UTF-8"?>
<html xmlns="http://www.w3.org/1999/xhtml" lang="en-gb">
<head>
<title>No Longer Human</title>
<meta content="urn:uuid:6757faf0-eef1-45d9-b2b3-7462350db7ba" name="Adept.expected.resource"/>
<meta content="text/html; charset=utf-8" http-equiv="Content-Type"/>
<link href="kindle:flow:0002?mime=text/css" rel="stylesheet" type="text/css"/>
<link href="kindle:flow:0001?mime=text/css" rel="stylesheet" type="text/css"/>
</head>
<body class="calibre" aid="0">
</body>
</html>
(example with BeautifulSoup, but I'm not attached to any parser in particular)
>>> soup = bs4.BeautifulSoup(html_markup)
>>> title_tag = soup.find('title')
>>> get_offsets_in_markup(title_tag) # <-------- how do I go about doing this?
(109, 139) # <----- source mapping info I want to get
>>> html_markup[109:139]
'<title>No Longer Human</title>'
I don't see this functionality in the APIs of any of the Python HTML parsers available. Can I hack it into one of the existing parsers? How would I go about doing that? Or is there another, better approach?
I realize that str(soup_element) serializes the element back into markup (and I can hypothetically recurse down the tree saving the start and end indices as I go), but the markup returned by doing that, although semantically equivalent to the original, doesn't match the original char-for-char. None of the available Python parsers do.
You can use regular expression to find corresponding element's start and indexes, and use those indexes in original string to find data:
import re
from bs4 import BeautifulSoup
from pathlib import Path
def get_offsets_in_markup(tag, html_markup):
elem = re.search(str(title_tag), html_markup)
return elem.start(), elem.end()
html_markup = Path('test.html').read_text()
soup = BeautifulSoup(html_markup, 'lxml')
title_tag = soup.find('title')
indexes = get_offsets_in_markup(title_tag, html_markup)
# -> (109, 139)
given_text = html_markup[indexes[0]:indexes[1]]
# -> <title>No Longer Human</title>
This is how test.html looks like:
<?xml version="1.0" encoding="UTF-8"?>
<html xmlns="http://www.w3.org/1999/xhtml" lang="en-gb">
<head>
<title>No Longer Human</title>
<meta content="urn:uuid:6757faf0-eef1-45d9-b2b3-7462350db7ba" name="Adept.e$
<meta content="text/html; charset=utf-8" http-equiv="Content-Type"/>
<link href="kindle:flow:0002?mime=text/css" rel="stylesheet" type="text/css"/>
<link href="kindle:flow:0001?mime=text/css" rel="stylesheet" type="text/css"/>
</head>
<body class="calibre" aid="0">
</body>
</html>
I am working on a simple way to wrap each sentence of an ebook formatted in HTML in span tags.
I am using a trained machine learning model to classify end of sentence punctuation (".!?" ...) and get the real sentences boundaries (ex: in U.S.A, "S" is not considered a sentence).
The problem is, in order to feed my model correct data, I need to first extract the text out of my HTML ebook (using BeautifulSoup's get_text('\n')).
Right now, I am able to wrap the output of get_text('\n') in span tags. But I can't just save that since I loose all the other tags used in the original HTML ebook.
Example HTML ebook sample:
<html><head><meta http-equiv="Content-Type" content="text/html;charset=utf-8" /><link href="style.css" rel="stylesheet" type="text/css" /><title> Name. Of the book. </title></head> ...
</div>
After get_text
Name. Of the book.
After running my algorithm:
<span>Name. Of the book.</span>
How can I get this output instead:
<html><head><meta http-equiv="Content-Type" content="text/html;charset=utf-8" /><link href="style.css" rel="stylesheet" type="text/css" /><title> <span>Name. Of the book.</span> </title></head> ...
</div>
Thank you in advance for your help!
You can use wrap() method (doc) to wrap the text into <span> tags - it will update the whole HTML structure.
Example:
data = '''<html><head><meta http-equiv="Content-Type" content="text/html;charset=utf-8" /><link href="style.css" rel="stylesheet" type="text/css" /><title> Name. Of the book. </title></head>'''
from bs4 import BeautifulSoup
soup = BeautifulSoup(data, 'html.parser')
print('Before:')
print('-' * 80)
print(soup.prettify())
print('-' * 80)
for text in soup.find_all(text=True):
text.wrap(soup.new_tag("span")) # use wrap() function to wrap the text into <span> tag
print('After:')
print('-' * 80)
print(soup.prettify())
print('-' * 80)
Prints (notice the <span> inside the <title> tag):
Before:
--------------------------------------------------------------------------------
<html>
<head>
<meta content="text/html;charset=utf-8" http-equiv="Content-Type"/>
<link href="style.css" rel="stylesheet" type="text/css"/>
<title>
Name. Of the book.
</title>
</head>
</html>
--------------------------------------------------------------------------------
After:
--------------------------------------------------------------------------------
<html>
<head>
<meta content="text/html;charset=utf-8" http-equiv="Content-Type"/>
<link href="style.css" rel="stylesheet" type="text/css"/>
<title>
<span>
Name. Of the book.
</span>
</title>
</head>
</html>
--------------------------------------------------------------------------------
Okay so I have a pretty naive but quite effective approach. You can get the entire html code first and then store it in a string and then use Regular Expression on it to extract the texts of the span tag.
This is the only way I can think of as of now. Hope this helps :)
I am trying to get the content of a meta tag. The problem is that BS4 can't parse the tag properly on some sites, where the tag is not closed as it should be. With tags as the example below, the output of my function includes tons of clutter including other tags such as scripts, links, etc. I believe the browser closes automatically the meta tag somewhere in the end of the head and this behavior confuses BS4.
My code works with this:
<meta name="description" content="content" />
and doesn't work with:
<meta name="description" content="content">
Here is the code of my BS4 function:
from bs4 import BeautifulSoup
html = BeautifulSoup(open('/path/file.html'), 'html.parser')
desc = html.find(attrs={'name':'description'})
print(desc)
Any way to make it work with those un-closed meta tags?
html5lib or lxml parser would handle the problem properly:
In [1]: from bs4 import BeautifulSoup
...:
...: data = """
...: <html>
...: <head>
...: <meta name="description" content="content">
...: <script>
...: var i = 0;
...: </script>
...: </head>
...: <body>
...: <div id="content">content</div>
...: </body>
...: </html>"""
...:
In [2]: BeautifulSoup(data, 'html.parser').find(attrs={'name': 'description'})
Out[2]: <meta content="content" name="description">\n<script>\n var i = 0;\n </script>\n</meta>
In [3]: BeautifulSoup(data, 'html5lib').find(attrs={'name': 'description'})
Out[3]: <meta content="content" name="description"/>
In [4]: BeautifulSoup(data, 'lxml').find(attrs={'name': 'description'})
Out[4]: <meta content="content" name="description"/>
Having get something new and hope it can give you some help, i think every time BeautifulSoup find an element without a proper end tag, then it will continue searching the next and next element until its parent tag end tag.Maybe you still don't understand my thought, and here i made a little demo:
hello.html
<!DOCTYPE html>
<html lang="en">
<meta name="description" content="content">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<div>
<p class="title"><b>The Dormouse's story</b>
<p class="story">Once upon a time there were three little sisters; and their names were
Elsie,
Lacie and
Tillie;
and they lived at the bottom of a well.</p>
</p></div>
</body>
</html>
and run like you done before and find result below:
<meta content="content" name="description">
<head>
<meta charset="utf-8">
<title>Title</title>
</meta></head>
<body>
...
</div></body>
</meta>
ok! BeautifulSoup generate the end meta tag automatically and whose position is after the </body> tag, but still can not see meta's parent end tag </html>, so what i mean is that end tag should reflect as the same position as its start tag. But i still can not convince myself such opinion so i make a test, delete <p class='title'> end tag so there is only one </p> tag in <div>...</div>, but after running
c = soup.find_all('p', attrs={'class':'title'})
print(c[0])
there are two </p> tags in result. So that's true as i said previously.
I have an html file with some self-closing tags, but BeautifulSoup doesn't like them.
from bs4 import BeautifulSoup
html = '<head><meta content="text/html" http-equiv="Content-Type"><meta charset="utf-8"></head>'
doc = BeautifulSoup(html, 'html.parser')
print doc.prettify()
prints
<head>
<meta content="text/html" http-equiv="Content-Type">
<meta charset="utf-8"/>
</meta>
</head>
Must I manually check if each tag is self-closing and modify appropriately, or is there a better way of handling this?
As you may already know, you can specify different parsers that BeautifulSoup would use internally. And, as noted in BeautifulSoup docs:
There are also differences between HTML parsers. If you give Beautiful
Soup a perfectly-formed HTML document, these differences won’t matter.
One parser will be faster than another, but they’ll all give you a
data structure that looks exactly like the original HTML document.
But if the document is not perfectly-formed, different parsers will
give different results.
In this particular case, both lxml and html5lib produce two separate meta tags:
In [4]: doc = BeautifulSoup(html, 'lxml')
In [5]: print(doc.prettify())
<html>
<head>
<meta content="text/html" http-equiv="Content-Type"/>
<meta charset="utf-8"/>
</head>
</html>
In [6]: doc = BeautifulSoup(html, 'html5lib')
In [7]: print(doc.prettify())
<html>
<head>
<meta content="text/html" http-equiv="Content-Type"/>
<meta charset="utf-8"/>
</head>
<body>
</body>
</html>
I want to catch some tags with BeautifulSoup: Some <p> tags, the <title> tag, some <meta> tags. But I want to catch them regardless of their case; I know that some sites do meta like this: <META> and I want to be able to catch that.
I noticed that BeautifulSoup is case-sensitive by default. How do I catch these tags in a non-case-sensitive way?
BeautifulSoup standardises the parse tree on input. It converts tags to lower-case. You don't have anything to worry about IMO.
You can use soup.findAll which should match case-insensitively:
import BeautifulSoup
html = '''<html>
<head>
<meta name="description" content="Free Web tutorials on HTML, CSS, XML" />
<META name="keywords" content="HTML, CSS, XML" />
<title>Test</title>
</head>
<body>
</body>
</html>'''
soup = BeautifulSoup.BeautifulSoup(html)
for x in soup.findAll('meta'):
print x
Result:
<meta name="description" content="Free Web tutorials on HTML, CSS, XML" />
<meta name="keywords" content="HTML, CSS, XML" />