How to get line numbers of the snippets matching a regexp?

Question

How is it possible to obtain the line numbers of all the text snippets matching a given regexp, within a file?

file_content = f.rea         


        

Answer 1

 with open(somefile, 'r') as f:
     line_numbers = [n for n, line in enumerate(f) if re.search(someRegexp, line)]

Answer 2

import re
reg="ha*"
count=0
f = open(somefile,'r')
while True:
        line= f.readline()
        if not line: break
        else:
                count+=1
                if re.search(reg,line):
                        print count,line