Selecting an entire paragraph by just matching a string

Question

Suppose I have two paragraphs while reading a file:

'Baa, baa, black sheep, have you any wool?
Yes sir, yes sir, three bags full!
One for the master
One for the dame'

'Mary had a little lamb,
its fleece was white as snow;
And everywhere that Mary went,
the lamb was sure to go.'

Is there any code (using regular expressions or something) that, if I search 'lamb', will select the entire second paragraph?

Answer 1

Assuming that the paragraphs are all in a single string, something like this should work:

def select_paragraph(text, word, delimiter='\n'):
    return [p for p in text.split(delimiter) if word in p]

Answer 2

This will select a paragraph containing lamb:

([^\']*(?=lamb)[^\']*)

DEMO

Here's python code:

import re
data = """
'Baa, baa, black sheep, have you any wool?
Yes sir, yes sir, three bags full!
One for the master
One for the dame'

'Mary had a little lamb,
its fleece was white as snow;
And everywhere that Mary went,
the lamb was sure to go.'
"""

match = re.search('([^\']*(?=lamb)[^\']*)',data)
print(match.group())

Output:

Mary had a little lamb,
its fleece was white as snow;
And everywhere that Mary went,
the lamb was sure to go.