How to make the program look for keywords in sentences?

Question

Python

Only 2 keywords and many sentences, some of which contain keywords.

Answer 1

Regular expressions (modulo re), in particular the marker \b - word boundary.
The "gate" regular will find both "gate" and "turn" and "collar" The
"\bgate\b" regular will find only "gate" but not "turn" / "collar".
But if you need word forms ("flying / flying / flying / flying"), then the task becomes more complicated.