About Python's built in sort() method

Question

What algorithm is the built in sort() method in Python using? Is it possible to have a look at the code for that method?

Answer 1

Sure! The code's here, starting with function islt and proceeding for QUITE a while;-). As Chris's comment suggests, it's C code. You'll also want to read this text file for a textual explanation, results, etc etc.

If you prefer reading Java code than C code, you could look at Joshua Bloch's implementation of timsort in and for Java (Joshua's also the guy who implemented, in 1997, the modified mergesort that's still used in Java, and one can hope that Java will eventually switch to his recent port of timsort).

Some explanation of the Java port of timsort is here, the diff is here (with pointers to all needed files), the key file is here -- FWIW, while I'm a better C programmer than Java programmer, in this case I find Joshua's Java code more readable overall than Tim's C code;-).

Answer 2

In early python-versions, the sort function implemented a modified version of quicksort. However, it was deemed unstable and as of 2.3 they switched to using an adaptive mergesort algorithm.

Answer 3

i heard the timsort is the best sorting algorithum because it works on the two sorting which has two advantages one has a low constant rate and other has the faster efficeincy they are the binary insertion sort and merge sort.

Answer 4

I just wanted to supply a very helpful link that I missed in Alex's otherwise comprehensive answer: A high-level explanation of Python's timsort (with graph visualizations!).

(Yes, the algorithm is basically known as Timsort now)