I would use filter: str_list = filter(None, str_list) str_list = filter(bool, str_list) str_list = filter(len, str_list) str_list = filter(lambda item: item, str_list) Python 3 returns an iterator from filter, so should be wrapped in a call to list() str_list = list(filter(None, str_list))
Here you have some alternatives: http://www.peterbe.com/plog/uniqifiers-benchmark Fastest one: def f7(seq): seen = set() seen_add = seen.add return [x for x in seq if not (x in seen or seen_add(x))] Why assign seen.add to seen_add instead of just calling seen.add? Python is a dynamic language, and resolving seen.add each iteration is more costly than resolving a … Read more
In Java 8: List<String> newList = Stream.concat(listOne.stream(), listTwo.stream()) .collect(Collectors.toList()); Java 16+: List<String> newList = Stream.concat(listOne.stream(), listTwo.stream()).toList();
You can find a short collection of useful list functions here. list.pop(index) >>> l = [‘a’, ‘b’, ‘c’, ‘d’] >>> l.pop(0) ‘a’ >>> l [‘b’, ‘c’, ‘d’] >>> del list[index] >>> l = [‘a’, ‘b’, ‘c’, ‘d’] >>> del l[0] >>> l [‘b’, ‘c’, ‘d’] >>> These both modify your original list. Others have suggested … Read more
Use str.join: >>> words = [‘this’, ‘is’, ‘a’, ‘sentence’] >>> ‘-‘.join(words) ‘this-is-a-sentence’ >>> ‘ ‘.join(words) ‘this is a sentence’
It is strange how much beauty varies for different people. I find the list comprehension much clearer than filter+lambda, but use whichever you find easier. There are two things that may slow down your use of filter. The first is the function call overhead: as soon as you use a Python function (whether created by … Read more
Use ”.join: xs = [‘1’, ‘2’, ‘3’] s=””.join(xs) If the list contains integers, convert the elements to string before joining them: xs = [1, 2, 3] s=””.join(str(x) for x in xs)
# To sort the list in place… ut.sort(key=lambda x: x.count, reverse=True) # To return a new list, use the sorted() built-in function… newlist = sorted(ut, key=lambda x: x.count, reverse=True) More on sorting by keys.
First declare your list properly, separated by commas. You can get the unique values by converting the list to a set. mylist = [‘nowplaying’, ‘PBS’, ‘PBS’, ‘nowplaying’, ‘job’, ‘debate’, ‘thenandnow’] myset = set(mylist) print(myset) If you use it further as a list, you should convert it back to a list by doing: mynewlist = list(myset) … Read more
Apart from tuples being immutable there is also a semantic distinction that should guide their usage. Tuples are heterogeneous data structures (i.e., their entries have different meanings), while lists are homogeneous sequences. Tuples have structure, lists have order. Using this distinction makes code more explicit and understandable. One example would be pairs of page and … Read more