Question

I have a code at the moment that takes a line from a .txt file and then turns it into a list, with the whitespace stripped.

Looks like this:

fd = open(filename,'rU')
chars = []
for line in fd:
    chars.append(line.strip())

return chars

The output looks like this:

['TTTTT', 'TTHHT', 'HHTHT', 'HHHHH', 'THTHT', '']

What I want to do here is turn the out put to look like this:

[['T', 'T', 'T', 'T', 'T'], ['T', 'T', 'H', 'H',  'T',] etc...]

I want to separate them into single elements, but also keep them within their original lists.

Answer 1

I don’t know why you want to do this, as you can do almost anything you can do with a list with a str — except change it.

Assuming you have a good reason, you probably want to change your loop to

for line in fd:
    chars.append(list(line.strip()))

or after the loop,

chars = map(list, chars)

Will do it. It will run list on each item in chars.

On Python 2, it will make a list out of the result.

On Python 3, you’ll need to do

chars = list(map(list, chars))

or

chars = [list(sublist) for sublist in chars]

if you want it back as a list-o-lists.