PYTHON

Biologists use a sequence of lettersA, C, T, and G to model a genome. A gene is a substring of a genome that starts after a triplet ATG and ends before a triplet TAG, TAA, or TGA . Furthermore, the length of a gene string is a multiple of 3 and the gene does not conta in any of the triplets ATG, TAG, TAA, and TGA.

Write a program that prompts the user to enter a genome and displays all genes in the genome. If no gene is found in the input sequence, the program displays no gene is found. Here are the sample runs:

>>>

========== RESTART: E:/HW3/HW3_4_genes.py ==========

Enter a genome string: TTATGTTTTAAGGATGGGGCGTTAGTT

TTT

GGGCGT

Enter a genome string: TGTGTGTATAT

no gene is found

>>>

Test with 4 more genome strings.

TGATGCTCTAAGGATGCGCCGTTGATT

TGATGCTCTAGAGATGCGCCGTTGAATAT

TGATGCGTCTAAGAGACTGCTCGCCGGTTGAATAT

TGATGGCTCCTATGAGAATGGCGCCCGTTTCGAAATAT