Regex to match specific number

I currently have the regex "(?<!mp){i}" which matches a specific number but it overmatches and includes 10, 11, 21, etc when I want to match 1. In short, it is matching as long as i contains the number in the string (if i=2 and the string contains "xxxxxx 24" it would also match, which I don’t want)

strings

xx 1.mp4
xx 10.mp4
xx21.mp4
xx1.mp4
xx 1 xx.mp4
xx.1.xxx.mp4
xx.11.xxx.mp4
xxx s1e3 xxx.mp4
xxx season 1 episode 3
xxx season 2 episode 1

expected outcome if trying to match where i=1

xx 1.mp4
xx1.mp4
xx 1 xx.mp4
xx.1.xxx.mp4
xxx season 2 episode 1

note: xxx s1e3 xxx.mp4 and xxx season 1 episode 3 was NOT match even though it contains 1 because it was followed by s and season. However, xxx season 2 episode 1 Should be match, since the "episode" contains 1

Another note: Ideally, it shouldn’t be limited to just 1, since I wouldn’t want to match 24 32 when I am trying to find a match for i=2, etc

I’ve tried

if re.search(rf"(?<!mp){i}", string):
                do something

it returns strings with 10,11, 21 100, etc when I am just searching for 1. Likewise with i=2