f = 'pi_million_digits.txt' f2= 'data' with open(f) as fh: lines = fh.readlines() s=[0] * 3 with open(f2) as fh2: line2s=fh2.readlines() i=0 for line in line2s: l=line.rstrip() s[i]=l i = i+1 pi_string = '' for line in lines: pi_string += line.strip() print(s) count=0 for i in s: if i in pi_string: count += 1 print(f"total count = {count}")