While trying to learn a little more about regular expressions, a tutorial suggested that you can use the \b
to match a word boundary. However, the following snippet in the Python interpreter does not work as expected:
>>> x = 'one two three'
>>> y = re.search("\btwo\b", x)
It should have been a match object if anything was matched, but it is None
.
Is the \b
expression not supported in Python or am I using it wrong?
Why don't you try
word = 'two'
re.compile(r'\b%s\b' % word, re.I)
Output:
>>> word = 'two'
>>> k = re.compile(r'\b%s\b' % word, re.I)
>>> x = 'one two three'
>>> y = k.search( x)
>>> y
<_sre.SRE_Match object at 0x100418850>
Also forgot to mention, you should be using raw strings in your code
>>> x = 'one two three'
>>> y = re.search(r"\btwo\b", x)
>>> y
<_sre.SRE_Match object at 0x100418a58>
>>>
This will work: re.search(r"\btwo\b", x)
When you write "\b"
in Python, it is a single character: "\x08"
. Either escape the backslash like this:
"\\b"
or write a raw string like this:
r"\b"