dna_visualization.py

import random, sys, time

PAUSE = 0.15 # (!) change between 0.0 - 0.5

# Individal rows of the DNA animation:
ROWS = [
    #123456789 <- Use this to measure the number of spaces:
    '          ##', # Index 0 has no {}.
    '         #{}-{}#',
    '        #{}---{}#',
    '       #{}-----{}#',
    '      #{}------{}#',
    '     #{}------{}#',
    '     #{}-----{}#',
    '      #{}---{}#',
    '      #{}-{}#',
    '       ##', # Index 9 has no {}.
    '      #{}-{}#',
    '      #{}---{}#',
    '     #{}-----{}#',
    '     #{}------{}#',
    '      #{}------{}#',
    '       #{}-----{}#',
    '        #{}---{}#',
    '          #{}-{}#']
#123456789 <-Used to measure the number of spaces:

try: 
    print('DNA Animation')
    print('Press Ctrl-C to quit...')
    time.sleep(2)
    rowIndex = 0

    while True: # Main program loop.
        # Increment rowIndex to draw next row:
        rowIndex = rowIndex + 1
        if rowIndex == len(ROWS):
            rowIndex = 0 

        # Row indexes 0 and 9 don't have nucleotides:
        if rowIndex == 0 or rowIndex == 9:
            print(ROWS[rowIndex])
            continue

        #Select random nucleotide pairs, guanine-cytosine and 
        #adenine-thymine:
        randomSelection = random.randint(1,4)
        if randomSelection == 1:
            leftNucleotide, rightNucleotide ='A', 'T'
        elif randomSelection == 2:
            leftNucleotide, rightNucleotide ='T', 'A'
        elif randomSelection == 3:
            leftNucleotide, rightNucleotide ='C', 'G'
        elif randomSelection == 4:
            leftNucleotide, rightNucleotide ='G', 'C'

        # Print the row.
        print(ROWS[rowIndex].format(leftNucleotide, rightNucleotide))
        time.sleep(PAUSE)
except KeyboardInterrupt:
    sys.exit() # When Ctrl-C is pressed end the program