Difference between + and *

Question

With regards to Regular expression, i am confused between the difference the + and * on the notes it tells me w+ matches one or more character and * matches 0 or more

Could someone please give an example to show the difference

Thanks

Answer 1 · 2019-10-06T23:39:25Z

October 6, 2019 11:39pm

use the * when you don't really care if a character is present because you are ok ignoring it use the + when you want to make sure the character is there for example, you could be working through a list that sometimes has Mr and sometimes does not. You might have a use case where you want to make sure you grab only the names where there is a Mr. title. Or you might have a different use case where you just care about the name and you are trying to match the name regardless of a title being present.

import re

data1 = 'abcxxxabc'
data2 = 'abcabc'

m2 = re.findall('x*abc', data1)
print(f"show a list of matches where there is an abc preceeded by zero or more x where the text is {data1}")
print(m2)

m3 = re.findall('x+abc', data1)
print(f"show a list of matches where there is an abc preceeded by one or more x where the text is {data1}")
print(m2)


m4 = re.findall('x*abc', data2)
print(f"show a list of matches where there is an abc preceeded by zero or more x where the text is {data2}")
print(m4)

m5 = re.findall('x+abc', data2)
print(f"show a list of matches where there is an abc preceeded by one or more x where the text is {data2}")
print(m5)

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Sohail Mirza

Sohail Mirza

Difference between + and *

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frankgenova

frankgenova

Sohail Mirza

Sohail Mirza