404 How do I concatenate two lists in Python? As of 3.9, these are the most popular stdlib methods for concatenating two (or more) lists in Python. ... * A solution will qualify as a generalized solution if it …

Jun 20, 2019 · My idea was to get the list once that the for cycle is done, dump it into the second list, then start a new cycle, dump the content of the first list again into the second but appending it, so the …

Oct 31, 2008 · The keyword when using append is Object. If you try to use extend and you pass in a dictionary, it will append the key, and not the whole hash to the end of the array.

Sep 20, 2010 · 240 This question already has answers here: What is the difference between Python's list methods append and extend? (20 answers)

Feb 23, 2015 · Here is what Python documents have to say about this: list.append (x): Add an item to the end of the list; equivalent to a [len (a):] = [x]. list.extend (L): Extend the list by appending all the …

Python lists are heterogeneous that is the elements in the same list can be any type of object. The expression: c.append(c) appends the object c what ever it may be to the list.

6 If you want to append to the lists of each key inside a dictionary, you can append new values to them using + operator (tested in Python 3.7):

Appending to list in Python dictionary [duplicate] Asked 11 years, 1 month ago Modified 10 years, 6 months ago Viewed 422k times

It seems awkward to test for a list at key b in the dictionary, then look for an a, then append a if it's not already there, every single time through the tuple digesting loop; but I haven't found a better way yet.

If your list of lists comes from a nested list comprehension, the problem can be solved more simply/directly by fixing the comprehension; please see How can I get a flat result from a list …