Pandas filtering for multiple substrings in series

Question

I need to filter rows in a pandas dataframe so that a specific string column contains at least one of a list of provided substrings. The substrings may have unu

Answer 1

Using a simpler example & ignore case (upper or lowercase)

Filtering and getting a binary vector:

I want to find all elements of a pd.Series, v, that contain "at" or "Og". And get 1 if the element contains the pattern or 0 if it doesn't.

I'll use the re:

import re

My vector:

v=pd.Series(['cAt','dog','the rat','mouse','froG'])

[Out]:

0        cAt
1        dog
2    the rat
3      mouse
4       froG

I want to find all elements of v that contain "at" or "Og". This is, I can define my pattern as:

pattern='at|Og'

Since I want a vector with 1s if the item contains the pattern or 0 if don't.

I create an unitary vector with the same length as v:

v_binary=[1]*len(v)

I obtain a boolenean s that is Trueif one element of vcontains the patternor Falseif it doesn't contain it.

s=v.str.contains(pattern, flags=re.IGNORECASE, regex=True)

To obtain the binary vector I multiply the v_binary*s:

v_binary*s

[Out]

0    1
1    1
2    1
3    0
4    1