A simple python program to transcript a DNA strand into a RNA one.

rna.py

"""
An RNA string is a string formed from the alphabet containing 'A', 'C', 'G', and 'U'.

Given a DNA string t corresponding to a coding strand, its transcribed RNA string u is formed by replacing all occurrences of 'T' in t with 'U' in u.

Given: A DNA string t having length at most 1000 nt.

Return: The transcribed RNA string of t.
"""

import os

imput_filepath = '/tmp/rosalind_rna.txt'

try:
    with open(imput_filepath) as line:
        dna = line.readline()

    print(str(dna.replace('T', 'U')))

              
except IOError as err:
    print('File Error : ' + str(err))