You could use an empty jQuery object instead of an array: var elements = $(); for(x = 0; x < 1000; x++) { elements = elements.add(‘<div>’+x+'</div>’); // or // var element = $(‘<div>’+x+'</div>’); // elements = elements.add(element); } $(‘body’).append(elements); This might be useful if you want to do stuff with newly generated element inside the … Read more
Python lists are mutable objects and here: plot_data = [[]] * len(positions) you are repeating the same list len(positions) times. >>> plot_data = [[]] * 3 >>> plot_data [[], [], []] >>> plot_data[0].append(1) >>> plot_data [[1], [1], [1]] >>> Each list in your list is a reference to the same object. You modify one, you … Read more
Vectors are not designed for prepending. You have only O(n) prepend: user=> (into [:foo] [:bar :baz]) [:foo :bar :baz] What you want is most likely a finger tree.
The poor performance you observe is caused by a bug in the Python garbage collector in the version you are using. Upgrade to Python 2.7, or 3.1 or above to regain the amoritized 0(1) behavior expected of list appending in Python. If you cannot upgrade, disable garbage collection as you build the list and turn … Read more
1. String otherString = “helen” + character; 2. otherString += character;
UPDATE [2022-01-08]: starting from version 1.4.0 Pandas supports appending to existing Excel sheet, preserving the old contents, “out of the box”! Good job Pandas Team! Excerpt from the ExcelWriter documentation: if_sheet_exists : {‘error’, ‘new’, ‘replace’, ‘overlay’}, default ‘error’ How to behave when trying to write to a sheet that already exists (append mode only). … … Read more
Here’s an update for PointZeroTwo’s answer in Swift 3.0, with one quick note – in the playground testing using a simple filepath works, but in my actual app I needed to build the URL using .documentDirectory (or which ever directory you chose to use for reading and writing – make sure it’s consistent throughout your … Read more
You need to append a copy, otherwise you are just adding references to the same dictionary over and over again: yourlist.append(yourdict.copy()) I used yourdict and yourlist instead of dict and list; you don’t want to mask the built-in types.
Info/Summary With bash scripting you can enclose commands in back ticks or parantheses. This works great for labling files, the following wil create a file name with the date appended to it. Methods Backticks – $ echo myfilename-“`date +”%d-%m-%Y”`” $(parantheses) – : $ echo myfilename-$(date +”%d-%m-%Y”) Example Usage: echo “Hello World” > “/tmp/hello-$(date +”%d-%m-%Y”).txt” (creates … Read more