Word Boundaries in Python Regular Expressions

The '\\b' command references a word boundary, while '\B' or '\\B' do not reference a boundary. Note that Python strictly uses double-slash escaping for word boundaries, while other commands allow a single slash. Let's see how these commands work with examples.

Example

Let's wrap each word in the symbol '!':

pythontxt = 'aaa aaa aaa'
print(re.sub('\\b', '!', txt))

Result of code execution:

python'!aaa! !aaa! !aaa!'

Example

Let's add the symbol '!' in the spaces between the letters:

pythontxt = 'aaa aaa aaa'
print(re.sub('\\B', '!', txt))

Result of code execution:

python'a!a!a a!a!a a!a!a'

Practical tasks

pythontxt = 'abc def xyz'

python'#abc# #def# #xyz#'

pythontxt = 'abc def xyz'

python'a+b+c d+e+f x+y+z'