Backreferences

Regular expressions in Python

Maria Eugenia Inzaugarat

Data Scientist

Genummerde groepen

text = "Python 3.0 was released on 12-03-2008."

information = re.search(r'(\d{1,2})-(\d{2})-(\d{4})', text)

information.group(3)

'2008'

information.group(0)

'12-03-2008'

text = "Austin, 78701"

cities = re.search(r"(?P<city>[A-Za-z]+).*?(?P<zipcode>\d{5})", text)

cities.group("city")

'Austin'

cities.group("zipcode")

'78701'

sentence = "I wish you a happy happy birthday!"

re.findall(r"(\w+)\s  ", sentence)

sentence = "I wish you a happy happy birthday!"

re.findall(r"(\w+)\s\1", sentence)

['happy']

sentence = "I wish you a happy happy birthday!"

re.sub(r"(\w+)\s\1", r"\1", sentence)

'I wish you a happy birthday!'

sentence = "Your new code number is 23434. Please, enter 23434 to open the door."

re.findall(r"(?P<code>\d{5}).*?(?P=code)", sentence)

['23434']

sentence = "This app is not working! It's repeating the last word word."
re.sub(r"(?P<word>\w+)\s(?P=word)", r"\g<word>", sentence)

'This app is not working! It's repeating the last word.'

Regular expressions in Python