Homework 2: Python Basics

1. Write a python program called print_triples.py. Print out all the numbers from 0 to 100 and print a * next to the numbers which are perfectly divisible by 3.

• Do this by making a loop which counts up from 0..100
• Check the number to see if it is divisible perfectly by 3 (no remainder)
• Print a * next to the number if that is the case

Output should look some like

0
1
2
3 *
4
5
6 *

2. Write a replacement for the unix tool word count: wc. The program should print out the number of lines in an input file - store your code in the script wc.py.

• Bonus for the more advanced - also print out the number words and characters found in the file.

3. Read in the codon table file and print some specific patterns. The file is codon_table_compact.txt and is provided in the homework template you will get when you clone the repository. It is also available codon_table_compact.txt. This file has 3 columns which list the 3 letter codon, the amino acid abbreviation, and the full amino acid name. Your program will be written in the script codon_table_count.py

• For each amino acid, print out the number of codons which code for it
• Print out the total number of amino acids and codons seen.
• Print out the number of Amino acids which are four-fold degerate (are encoded by 4 or more codons). Also print out these amino acids at the end.

The report can look something like:

Amino acid X is encoded by Y codons
...
...
===
There are X total amino acids and X codons
There are X AAs which are four-fold or six-fold degenerate
These AAs are:
  X
  Y
  Z