Did you already try to sort a list of tuples? And when you saw the result,
it wasn’t quiet what you expected? Well, this happend to me when I went deeper
into Python and I suppose, it also happend to you, since you are looking for
a solution. This defenitely shows that you are an advanced Python programmer already!<\/p>\n
Use Python’s built-in sorted() function or call the method sort() on the list
you want to sort. Both of them have an optional parameter key which accepts a
function. Pass a function here which computes a key-value from each tuple in the list to sort
the tuples by their computed key-values.
Example for sorting a list of tuples by their second entry:<\/p>\n
lst = [(1, 2), (2, 3), (0, 3)]\nlst.sort(key=lambda x: x[1])<\/pre>\nHow to Sort a List of Tuples by Any Element or Custom Value?<\/h2>\n
Let’s first frame our problem in more detail: We have a list of tuples which we want to sort by
their second element or sum of elements or anything else which is not the first element of the list.
The default behavior of both, sort() and sorted(), is taking the first entry of each tuple to
sort the list of tuples. This is what may lead to surprises for beginners.<\/p>\nSuppose, we want to sort a list of items like this one:<\/p>\n
items = [ (\"apple\", 1.5), (\"pear\", 2.3), (\"egg\", 0.5), (\"cherry\", 0.2),\n]<\/pre>\n