Question

I have read a cvs file and I would like to create a dictionary from the information I have on that file. I´ve tried to use class csv.DictReader to that propose but it didnt gave me the results i wanted.

Now i am reading the file like this:

size_reader = csv.reader(f,dialect='excel-tab')

and I have as result this:

['chr1', '249250621']
['chr2', '243199373']
['chr3', '198022430']
['chr4', '191154276']
['chr5', '180915260']

I would like to make a dictionary with this structure:

dict ['chr4'] = 191154276
dict ['chr5'] = 180915260
dict ['chr2'] = 243199373

I tried regular expressions to split the elements the lines on the file but I had no success with it, maybe i used the wrong characters in the split function. Could you give some suggestion of how to separate the elements and built the dictionary?

Answer 1

Just convert it to a dict directly:

 result = dict(size_reader)

This takes each two-column result from your size_reader CVS reader and uses that as the key and value for a python dictionary.

To convert each value to integers, you’d need to use a dict comprehension to process each value:

result = {k: int(v) for k, v in size_reader}