#!/usr/bin/env python

# open the input file 
file = open("seq.txt") 

# open the output file 
output = open("trimmed.txt", "w") 

# go through the input file one line at a time 
for dna in file: 
    # calculate the position of the last character 
    last_character_position = len(dna) 
    # get the substring from the 15th character to the end 
    trimmed_dna = dna[14:last_character_position] 
    # print out the trimmed sequence 
    output.write(trimmed_dna) 
    # print out the length to the screen 
    print("processed sequence with length " + str(len(trimmed_dna))) 
