Python has supported the key= for .sort since 2.4, that is year 2004, it does the Schwartzian transform within the sorting code, in C; thus this method is useful only on Pythons 2.0-2.3. all …

445 sorted() returns a new sorted list, leaving the original list unaffected. list.sort() sorts the list in-place, mutating the list indices, and returns None (like all in-place operations). sorted() works …

I don't quite understand the syntax behind the sorted() argument: key=lambda variable: variable[0] Isn't lambda arbitrary? Why is variable stated twice in what looks like a dict?

I saw some examples using built-in functions like sorted, sum etc. that use key=lambda. What does lambda mean here? How does it work? For the general computer science concept of a …

3 key is a function that will be called to transform the collection's items before they are compared. The parameter passed to key must be something that is callable. The use of lambda creates …

Apr 20, 2010 · If there is another variable aliasing the original list, its value afterwards will not have the elements in their original order, nor in descending order; the alias will point at a list …

Jun 8, 2012 · In Python 2.7, how does Python's built-in sorted function work - what algorithm does it use?

One simple way to see it is that the sorted() (or list.sort()) function in Python operates on a single key at a time. It builds a key list in a single pass through the list elements.

Aug 30, 2008 · @Dmitry This is because you are printing the return value of the sort function called in [1, 2, 3].sort(). As sort() sorts the list in place (ie, changes the list directly), it doesn't …

Nov 20, 2010 · Here's one way: You basically re-write your sort function to take a list of sort functions, each sort function compares the attributes you want to test, on each sort test, you …