Genetic sequence

A genetic sequence (DNA sequence) can be represented by a string with a sequence of capital letters A, C, G and T that represent nucleotides 1.

Save all functions into the same file named dna.py.

1. Write function isdna() that takes a string (str), and returns True if it is a DNA or False otherwise. See the following examples:

   >>> isdna('AAAGTCTGAC')
   True
   >>> isdna('AAAGTCXGAC')
   False
   
   

   Note

   More tests are provided in the test-isdna.txt file.

2. Write function similar_dna() that takes two strings (str) with the same length and with a dna each, and returns the percentage (float) of matching pairs with respect to the total length. A matching pair is a pair of nucleotides one in each sequence which are equal and at the same position. See the following examples:

   >>> round(similar_dna('AGTC', 'AATA'), 2)
   50.0
   >>> round(similar_dna('AGTCT', 'AGTCT'), 2)
   100.0
   >>> round(similar_dna('TTCCG', 'AATAA'), 2)
   0.0
   >>> round(similar_dna('AAGTCCTTGA', 'AGCTCCTGGA'), 2)
   70.0
   >>> round(similar_dna('TGCCGAATGGACTTG', 'GGATTCGAATCTTGC'), 2)
   13.33
   

   Note

   More tests are provided in the test-similar.txt file.

Solution

A solution of these functions is provided in the dna.py file.