Question

Write a Python function makeDict() that takes a filename as a parameter. The file contains DNA sequences in Fasta format,

for example:

>human

ATACA

>mouse

AAAAAACT

The function returns a dictionary of key:value pairs, where the key is the taxon name and the valus is the total number of 'A' and 'T' occurrences. For example, for if the file contains the data from the example above the function should return: {'human':4,'mouse':7}

Answer 1

OUTPUT :

CODE:

def makeDict(filename):
#Open file
f = open(filename)
#Read all lines
lines = f.readlines()
#Initiaize dictionary for ans
ans = {}
for i in range(0,len(lines),2):
#Read taxon and sequence
taxon = lines[i].strip()[1:]
sequence = lines[i+1].strip()
#A, T counter
AT = 0
#Loop through sequence to find A, T Count
for s in sequence:
if s in 'AT':
AT = AT+1
ans[taxon] = AT
return ans
  
seq.txt:

>human
ATACA
>mouse
AAAAAACT