How do you sort a list containing tuples?

How do you sort a list containing tuples?

Use a lambda function as an argument to sort() to sort a list of tuples by the second value. Call list. sort(key=None) with list as a list of tuples and key set to lambda x: x[1] to sort list by the second element of each tuple.

Can we sort tuples in Python?

In Python, there are two ways, sort() and sorted() , to sort lists ( list ) in ascending or descending order. If you want to sort strings ( str ) or tuples ( tuple ), use sorted() .

How do you sort a list in descending order python?

If you want to sort in a descending order, all you have to do is add the parameter reverse = True to either the sort or sorted functions. They both accept it!

What is the difference between sorting and filtering?

Essentially, sorting and filtering are tools that let you organize your data. When you sort data, you are putting it in order. Filtering data lets you hide unimportant data and focus only on the data you're interested in.

Is sorted function in Python?

Python sorted() Function The sorted() function returns a sorted list of the specified iterable object. ... Strings are sorted alphabetically, and numbers are sorted numerically. Note: You cannot sort a list that contains BOTH string values AND numeric values.

Can you sort a set?

A set is an unordered collection with no duplicate elements. Set objects also support mathematical operations like union, intersection, difference, and symmetric difference. That means you will never be able to sort items inside a set*.

How do I sort a LinkedHashSet?

Different ways to sort LinkedHashSet :

  1. Convert LinkedHashSet to TreeSet for natural-ordering.
  2. Convert LinkedHashSet to TreeSet for reverse-ordering by providing Comparator based customized-sorting logic.
  3. Using ArrayList and Collections class' utility method sort();

How do you sort TreeSet?

The TreeSet implementation is sorting by the lexicographic order of the string values you insert. If you want to sort by the integer value, then you'll need to do as these others suggested and create a new object and override the compareTo method, or use your own comparator.

How do you sort an ArrayList?

Approach: An ArrayList can be Sorted by using the sort() method of the Collections Class in Java. This sort() method takes the collection to be sorted as the parameter and returns a Collection sorted in the Ascending Order by default.

Which is the fastest sorting method?

The time complexity of Quicksort is O(n log n) in the best case, O(n log n) in the average case, and O(n^2) in the worst case. But because it has the best performance in the average case for most inputs, Quicksort is generally considered the “fastestsorting algorithm.

How do you sort an ArrayList in alphabetical order?

To sort the ArrayList, you need to simply call the Collections. sort() method passing the ArrayList object populated with country names. This method will sort the elements (country names) of the ArrayList using natural ordering (alphabetically in ascending order).

Can you sort a HashMap?

HashMap is not meant to keep entries in sorted order, but if you have to sort HashMap based upon keys or values, you can do that in Java. Sorting HashMap on keys is quite easy, all you need to do is to create a TreeMap by copying entries from HashMap. ... This is similar of how you sort an ArrayList in Java.

How do I sort HashSet?


  1. Create new HashSet object.
  2. Store HashSet contents into ArrayList using inter-conversion constructor.
  3. Finally, invoke Collections. sort(al); method to sort elements in ascending order.
  4. Note: similarly elements can be sorted in descending order as well using Comparator.

How do you sort a HashMap in reverse order?

Below are the steps:

  1. Obtain stream from Set view of the mappings contained in the map.
  2. Sort the stream in reverse order of keys using Stream. sorted() method.
  3. Construct a LinkedHashMap from the stream using Stream. collect() with Collectors. toMap() .

How do I sort a TreeMap in reverse order?

By default TreeMap elements in Java are sorted in ascending order of keys. However, we can create the TreeMap in reverse order using Collections. reverseOrder() method in Java and display the elements in descending order of keys. The Collections.

Why NULL is not allowed in TreeMap?

Null Keys and Null Values What if we try to add one more element with a null key? TreeMap sorts elements in natural order and doesn't allow null keys because compareTo() method throws NullPointerException if compared with null.