Functions

GC Content 2


This is a follow up to GC Content 1.

A colleague has produced a file with one DNA sequence on each line. Download the file and load it into Python using numpy.loadtxt(). You will need to use the optional argument dtype = str to tell loadtxt() that the data is composed of strings.

Write a function to calculate GC content. GC content is the percentage of bases that are either G or C as a percentage of total base pairs. Your function should take a dna sequence as input and return the GC-content of that sequence. Print the result for each sequence.

Before we knew about functions we had to take each dna sequence one at a time and then rewrite or copy-paste the same code to analyze each one. Isn’t this better?

[click here for output]