CODEWITHSUNDEEP
pythonregexdictionary
Irshad Bhat
Irshad Bhat

Reputation: 8709

How to use dictionary inside regex in python?

Using a variable inside regex is easy and one way of achieving this is as:

>>> z = '23'
>>> re.sub(r'p[kv]', r"%s" %z, 'pvkkpkvkk')
'23kk23vkk'

But what if the replacement values are stored in a dictionary as:

d = {'k':'23', 'v':'24'}

and I want to use the dictionary to substitute the replacement values. I want something like this:

re.sub(r'p([kv])', r"%s" %d[\1], 'pvkkpkvkk')

I know this won't work. Please help me out to find the correct regex. Expected output is same as above.

Upvotes: 1

Views: 66

Answers (1)

jonrsharpe
jonrsharpe

Reputation: 122036

You can pass an arbitrary function, that takes a single match object and returns a string to replace it, as the repl for re.sub; for example:

>>> import re
>>> d = {'k': '23', 'v': '24'}
>>> re.sub(
    r'p([kv])',
    lambda match: d[match.group()[1]],
    'pvkkpkvkk',
)
'24kk23vkk'

Upvotes: 2

Related Questions