dna_to_rna

#This is a general purpose program to translate a DNA into a RNA strand.
#The exercice can be found here: https://rosalind.info/problems/rna/
#The user can either paste a DNA sequence or give the .txt file pathway to it. 

def transcribing_sequence(sequence):
    #formating the sequence and changing T for U:
    sequence = sequence.upper()
    transcribed_sequence = sequence.replace('T', 'U')
    print(transcribed_sequence)


#asking the user
choice = int(input('Type 1 to enter the .txt file pathway or 2 to paste your sequence: '))

#reading a file or the paste from the user 
if choice == 1:
    dir_pathway = input('Type the file pathway. If it is already on this program file, just type <filename.txt>: ')
    file = open(f"{dir_pathway}", 'r')
    sequence_nuc = file.read()
elif choice == 2: 
    sequence_nuc = input('Paste your sequence here: ')

#calling the function
transcribing_sequence(sequence_nuc)

#closing the file
if choice == 1: 
  file.close()