Python - Find line number from text file

Question

I'm writing code that looks in a text file, and sees if the input is in there.

E.g.,

I input "pizza"

My textfile contains:

bread
pizza
pasta
tomato

Is there a way to print the line number the word pizza is on?

Answer 1

with open('test.txt') as f:
    content = f.readlines()

index = [x for x in range(len(content)) if 'pizza' in content[x].lower()]

Part (1) of the code reads each line as a separate list in variable "content".

Part (2) populates out the line # of content only if 'pizza' exists in that line. [x for x in range(len(content))] simply populates all index values, while 'if 'pizza' in content[x].lower()' keeps the line # that matches the string.