Lab 5: Gene Detection

Web-CAT: Submit Python programs to this automated grading platform.

Task Outline

Due Date: Friday, October 18, 2019
Total Points: 10
Implement a Python program that determines which gene is present in a DNA sequence.

DNA is often described as a double helix of molecules known as nucleotides. Only four DNA nucleotides exist, and they are known by the labels A, C, G, and T. This means that we can conveniently represent a DNA sequence with a Python text string.
A cluster of three nucleotides is called a codon, and they represent amino acids which are present in DNA. For example, ATG is a codon which occurs throughout a DNA sequence. Codons are significant, because they are markers which indicate the presence of a gene.
ATG is the start codon which marks the beginning of a gene sequence. All of the nucleotides which are present, right up to, and including the stop codon are part of the gene.

Consider the following DNA sequence: ATATGTAGCTAGCATAATA
The start codon is ATG, and the stop codon for this example is TAA. Note that there are 9 nucleotides between these codons: AT ATGTAGCTAGCATAA TA
Therefore, the gene sequence which results from these codons is: ATGTAGCTAGCATAA

Note that we will not consider the case where a gene is absent from a DNA sequence. All of the DNA sequences used in the test benches have exactly one gene for you to find.
Also, each of the DNA sequences will have exactly one stop codon for your program to locate. In other words, there will not be multiple stop codons in the gene sequences.

Description	File Size	File Name
`Python` Source Code for Gene Detection	1.4KB	lab05.zip

Contents of lab05.zip:

Lab05GeneDetection/
├── genedetection.py
└── testgenedetection.py

Write a Python program in the file genedetection.py that finds and displays a single gene which is present in a DNA sequence.
You will write your solution in a function called findgene(dna, stopcodon) right below the place where it says: YOUR CODE HERE
When the function call findgene("ATATGTAGCTAGCATAATA", "TAA") is executed, the output of the program should be: ATGTAGCTAGCATAA

Run the file testgenedetection.py to execute the PyUnit test bench. PyUnit indicates a successful test with an OK output, and an unsuccessful test with a FAIL output.