3642302920 pyth split 1 4537

Simpo PDF Merge and Split Unregistered Version - http://www.simpopdf.com... Nieminen Dirk Roose Tamar Schlick Simpo PDF Merge and Split Unregistered Version - http://www.simpopdf.com...

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Texts in Computational Science

Editors

Timothy J Barth

Michael Griebel

David E Keyes

Risto M Nieminen

Dirk Roose

Tamar Schlick

Simpo PDF Merge and Split Unregistered Version - http://www.simpopdf.com

Hans Petter Langtangen

A Primer on Scientific

Programming

with Python

Third Edition

Simpo PDF Merge and Split Unregistered Version - http://www.simpopdf.com

Consider the function get_base_counts(dna) (from Chapter 6.6.3),

which counts how many times A, C, G, and Tappears in the string dna:

Unfortunately, this function crashes if other letters appear in dna.

Write an enhanced function get_base_counts2which solves this

prob-lem Test it on a string like ’ADLSTTLLD’ Name of program file:

def get_base_counts(dna):

counts = {’A’: 0, ’T’: 0, ’G’: 0, ’C’: 0}

for base in dna:

counts[base] += 1 return counts

Exercise 6.32 Find proportion of bases inside/outside exons.

Consider the lactase gene as described in Chapters 6.6.4and 6.6.5

What is the proportion of base A inside and outside exons of the

lac-tase gene? Write a functionget_exons, which returns all the substrings

of the exon regions concatenated, and a function get_introns, which

returns all the substrings between the exon regions concatenated The

function get_base_frequencies from Chapter 6.6.3 can then be used

to analyze the frequencies of bases A, C, G, and T in the two strings