Pyqt range input widget and python ranges

Question

I want to create pyqt widget like in MS Office or OOo print dialogs, that allows to input sets of ranges like "1, 3-4, 7-9". Does python have built-in tool or third party package for converting such strings into lists? For example:

"1, 3-4, 7-9" => [1,3,4,7,8,9]

ps: How this widget called?

Answer 1

Not sure if there's a built-in or a third party package available for this, but something like this should do it:

from itertools import chain
def my_range(*args):
    args = map(int,args)                                                               
    if len(args) == 1:
        return args
    return range(args[0], args[1]+1)

def func(strs):
    return list(chain.from_iterable(my_range(*x.split('-')) for x in strs.split(', ')))
strs = "1, 3-4, 7-9"
print func(strs)
#[1, 3, 4, 7, 8, 9]

Answer 2

Made my own version without itertools.

def expander(inpt):
    ret = []
    for token in inpt.split(','):
        if '-' in token:
            a, b = token.strip().split('-')
            ret.extend(range(int(a), int(b)+1))
        else:
            ret.append(int(token))
    return ret

print(expander('1, 3-4, 7-9'))

Keep in mind it would be healthy to check this string with regex.