How to load a big text file efficiently in python

Question

I have a text file containing 7000 lines of strings. I got to search for a specific string based upon few params.

Some are saying that the below code wouldn't be efficient (speed and memory usage).

f = open("file.txt")
data = f.read().split() # strings as list

1. First of all, if don't even make it as a list, how would I even start searching at all?
2. Is it efficient to load the entire file? If not, how to do it?
3. To filter anything, we need to search for that we need to read it right!

A bit confused

Answer 1

iterate over each line of the file, without storing it. This will make for program memory Efficient.

with open(filname) as f:
   for line in f:
      if "search_term" in line:
           break