itertools

I have a list of integers, and I want to generate a list containing a list of all the continuous integers. #I have: full_list = [0,1,2,3,10,11,12,59] #I want: continuous_integers = [[0,1,2,3], [10,11,12], [59]] I have the following which works, but seems like a poor way to do it: sub_list = [] continuous_list = [] for x in full_list: if sub_list == []: sub_list.append(x) elif x-1 in sub_list: sub_list.append(x) else: continuous_list.append(sub_list) sub_list = [x] continuous_list.append(sub_list) I've seen other questions suggesting that itertools.groupby is an efficient way to do this, but I

I need to generate all possible pairings, but with the constraint that a particular pairing only occurs once in the results. So for example: import itertools for perm in itertools.permutations(range(9)): print zip(perm[::2], perm[1::2]) generates all possible two-paired permutations; here's a small subset of the output: ... [(8, 4), (7, 6), (5, 3), (0, 2)] [(8, 4), (7, 6), (5, 3), (1, 0)] [(8, 4), (7, 6), (5, 3), (1, 2)] [(8, 4), (7, 6), (5, 3), (2, 0)] [(8, 4), (7, 6), (5, 3), (2, 1)] [(8, 5), (0, 1), (2, 3), (4, 6)] [(8, 5), (0, 1), (2, 3), (4, 7)] [(8, 5), (0, 1), (2, 3), (6, 4)] [(8, 5),

Well, I was using itertools.cycle().next() method with Python 2.6.6, but now that I updated to 3.2 I noticed that itertools.cycle() object has no method next() . I used it to cycle a string in the spin() method of a Spinner class. So if we cycle the tuple ('|', '/', '-', '\\', '|', '/', '-') , it'll print: | , / , - , \ , | , / , - , | , / and so on... I've searched the release notes of Python 3.0, 3.1 and 3.2 and didn't noticed any change on this. When this have changed? Is there any simple alternative to achieve the same functionality as before? Thank you in advance. d0ugal iter.next() was

I'm trying to write a function, in an elegant way, that will group a list of dictionaries and aggregate (sum) the values of like-keys. Example: my_dataset = [ { 'date': datetime.date(2013, 1, 1), 'id': 99, 'value1': 10, 'value2': 10 }, { 'date': datetime.date(2013, 1, 1), 'id': 98, 'value1': 10, 'value2': 10 }, { 'date': datetime.date(2013, 1, 2), 'id' 99, 'value1': 10, 'value2': 10 } ] group_and_sum_dataset(my_dataset, 'date', ['value1', 'value2']) """ Should return: [ { 'date': datetime.date(2013, 1, 1), 'value1': 20, 'value2': 20 }, { 'date': datetime.date(2013, 1, 2), 'value1': 10, 'value2

I am searching for a middle ground between Python's zip and zip_longest functions (from the itertools module), that exhausts all given iterators, but does not fill in anything. So, for example, it should transpose tuples like so: (11, 12, 13 ), (11, 21, 31, 41), (21, 22, 23, 24), --> (12, 22, 32, 42), (31, 32 ), (13, 23, 43), (41, 42, 43, 44), ( 24, 44) (Spaces added for nicer graphical alignment.) I managed to compose a crude a solution by cleaning out the fillvalue s after zip_longest . def zip_discard(*iterables, sentinel = object()): return map( partial(filter, partial(is_not, sentinel)),

In Python, given a list of sorted integers, I would to group them by consecutive values and tolerate gaps of 1. For instance, given a list my_list : In [66]: my_list Out[66]: [0, 1, 2, 3, 5, 6, 10, 11, 15, 16, 18, 19, 20] I would like the following output: [[0, 1, 2, 3, 5, 6], [10, 11], [15, 16, 18, 19, 20]] Now, if I didn't have to tolerate gaps of 1, I could apply the neat solution explained here : import itertools import operator results = [] for k, g in itertools.groupby(enumerate(my_list), lambda (i,x):i-x): group = map(operator.itemgetter(1), g) results.append(group) Is there a way to