python Programming Glossary: groupby

How to count the frequency of the elements in a list?

http://stackoverflow.com/questions/2161752/how-to-count-the-frequency-of-the-elements-in-a-list

do this a 1 1 1 1 2 2 2 2 3 3 4 5 5 from itertools import groupby len list group for key group in groupby a Output 4 4 2 1 2 ..

Python: removing duplicates from a list of lists

http://stackoverflow.com/questions/2213923/python-removing-duplicates-from-a-list-of-lists

i for i in xrange len ks if i 0 or ks i ks i 1 with Timer 'groupby' for i in xrange N k sorted k dedup list k for k _ in itertools.groupby.. i in xrange N k sorted k dedup list k for k _ in itertools.groupby k with Timer 'loop in' for i in xrange N new_k for elem in k.. lists. For long lists it's faster then everyone except groupby method. Does this make sense For short list the one in the code..

What's the most Pythonic way to identify consecutive duplicates in a list?

http://stackoverflow.com/questions/6352425/whats-the-most-pythonic-way-to-identify-consecutive-duplicates-in-a-list

share improve this question from itertools import groupby L 0 0 0 3 3 2 5 2 6 6 grouped_L k sum 1 for i in g for k g in.. 0 0 3 3 2 5 2 6 6 grouped_L k sum 1 for i in g for k g in groupby L # Or k len list g but that creates an intermediate list grouped_L..

How do I use Python's itertools.groupby()?

http://stackoverflow.com/questions/773/how-do-i-use-pythons-itertools-groupby

do I use Python's itertools.groupby I haven't been able to find an understandable explanation of.. explanation of how to actually use Python's itertools.groupby function. What I'm trying to do is this Take a list in this.. a simple list of numbers. So how do I use of itertools.groupby Is there another technique I should be using Pointers to good..

python dict.add_by_value(dict_2)?

http://stackoverflow.com/questions/877295/python-dict-add-by-valuedict-2

Update Still loking for more concise solutions. Maybe groupby can help The solution I've come up with using reduce groupby.. can help The solution I've come up with using reduce groupby isn't actually concise from itertools import groupby from operator.. groupby isn't actually concise from itertools import groupby from operator import itemgetter add c dict i reduce add map..