How can I sort a List alphabetically?
Assuming that those are Strings, use the convenient static method sort… java.util.Collections.sort(listOfCountryNames)
list
How to find all positions of the maximum value in a list?
a.index(max(a)) will tell you the index of the first instance of the largest valued element of list a.
How do I check if there are duplicates in a flat list?
Use set() to remove duplicates if all values are hashable: >>> your_list = [‘one’, ‘two’, ‘one’] >>> len(your_list) != len(set(your_list)) True
How to randomize two ArrayLists in the same fashion?
Use Collections.shuffle() twice, with two Random objects initialized with the same seed: long seed = System.nanoTime(); Collections.shuffle(fileList, new Random(seed)); Collections.shuffle(imgList, new Random(seed)); Using two Random objects with the same seed ensures that both lists will be shuffled in exactly the same way. This allows for two separate collections.
How to print out all the elements of a List in Java?
The following is compact and avoids the loop in your example code (and gives you nice commas): System.out.println(Arrays.toString(list.toArray())); However, as others have pointed out, if you don’t have sensible toString() methods implemented for the objects inside the list, you will get the object pointers (hash codes, in fact) you’re observing. This is true whether they’re … Read more
When to use a linked list over an array/array list?
Linked lists are preferable over arrays when: you need constant-time insertions/deletions from the list (such as in real-time computing where time predictability is absolutely critical) you don’t know how many items will be in the list. With arrays, you may need to re-declare and copy memory if the array grows too big you don’t need … Read more
Why is it string.join(list) instead of list.join(string)?
It’s because any iterable can be joined (e.g, list, tuple, dict, set), but its contents and the “joiner” must be strings. For example: ‘_’.join([‘welcome’, ‘to’, ‘stack’, ‘overflow’]) ‘_’.join((‘welcome’, ‘to’, ‘stack’, ‘overflow’)) ‘welcome_to_stack_overflow’ Using something other than strings will raise the following error: TypeError: sequence item 0: expected str instance, int found
Combining two sorted lists in Python
is there a smarter way to do this in Python This hasn’t been mentioned, so I’ll go ahead – there is a merge stdlib function in the heapq module of python 2.6+. If all you’re looking to do is getting things done, this might be a better idea. Of course, if you want to implement … Read more
List comprehension vs generator expression’s weird timeit results?
Expanding on Paulo’s answer, generator expressions are often slower than list comprehensions because of the overhead of function calls. In this case, the short-circuiting behavior of in offsets that slowness if the item is found fairly early, but otherwise, the pattern holds. I ran a simple script through the profiler for a more detailed analysis. … Read more
stale element reference: element is not attached to the page document
What is the line which gives exception ?? The reason for this is because the element to which you have referred is removed from the DOM structure I was facing the same problem while working with IEDriver. The reason was because javascript loaded the element one more time after i have referred so my date … Read more