Search Multiple Strings (from File) in a file and print the line

Question

Again apologies for been noob here: Trying below code for searching multiple strings read from keywords and search in f and printing the line. It works if I have on

Answer 1

One of the challenges of looking for keywords is defining what you mean by keyword and how a file's contents should be parsed to find the full set of keywords. If "aa" is a keyword, should it match "aaa" or maybe ""aa()"? Can a keyword have numbers in it?

A simple solution is to say that keywords are alphabetic only and should match contiguous alphabetic strings exactly, ignoring case. Further, matches should be considered line by line, not sentence by sentence. We can use a regex to find alphabetic sequences and sets to check containment like so:

keys.txt

aa bb 

test.txt

aa is good
AA is good
bb is good
cc is not good
aaa is not good

test.py

import re

keyfile = "keys.txt"
testfile = "test.txt"

keys = set(key.lower() for key in 
    re.findall(r'\w+', open(keyfile , "r").readline()))

with open(testfile) as f:
    for line in f:
        words = set(word.lower() for word in re.findall(r'\w+', line))
        if keys & words:
            print(line, end='')

Result:

aa is good
AA is good
bb is good

Add more rules for what you mean by a match and it gets more complicated.

EDIT

Suppose you have one keyword per line and you just want a substring match (that is, "aa" matches "aaa") instead of a keyword search, you could do

keyfile = "keys.txt"
testfile = "test.txt"

keys = [key for key in (line.strip() for line in open(keyfile)) if key]

with open(testfile) as f:
    for line in f:
        for key in keys:
            if key in line:
                print(line, end='')
                break

But I'm just guessing what your criteria are.