In this article, we’ll look at how to sort a dictionary in Python. We’ll first take a look at the built-in sorted() function and then see how to use the operator module’s itemgetter() function to achieve the same result. Sorting a Dictionary With the sorted() Function
The sorted() function can be used to sort a dictionary by key or value. To sort a dictionary by key, we can use the following syntax:
- sorted(dictionary, key=lambda k: dictionary.get(k))
How to sort a dictionary in python
- Get the dictionary.
- Use the sorted function and operator module.
- We can also use the lambda function to sort by key as well.
- That’s it! Our dictionary is now sorted by key.
How to create a dictionary in Python
A dictionary is a data type in Python that is used to store data in a key-value format. A dictionary can be created in two ways:
- With the built-in dict() function
- With curly braces {}
- Dictionaries are mutable, which means they can be changed after they have been created.
- Keys in a dictionary must be unique.
- Values in a dictionary can be repeated.
- Dictionaries are unordered, which means that the order in which the key-value pairs are added to the dictionary is not preserved.
How to access and modify elements in a dictionary in Python
Once a dictionary has been created, we can access and modify its elements by using square brackets [] to index into the dictionary. We can also use the built-in get() method to access values in a dictionary.
If we try to access a key that doesn’t exist in the dictionary, we’ll get a KeyError.
- We can use the in keyword to check if a key exists in a dictionary.
- We can use the del keyword to delete keys from a dictionary.
- We can use the pop() method to remove and return an element from a dictionary.
- We can use the update() method to add multiple key-value pairs to a dictionary at once.
How to iterate through the elements of a dictionary in Python
We can iterate through the elements of a dictionary using a for loop.When we iterate through a dictionary, we’ll get its key-value pairs in an arbitrary order.If we want to preserve the order of the dictionary’s elements, we can use the sorted() function to sort the dictionary before we iterate through it.
How to delete items from a dictionary in Python
- We can delete items from a dictionary using the del keyword or the pop() method.
- The del keyword deletes an entire dictionary.
- The pop() method removes and returns an element from a dictionary. If we don’t specify a key, it will remove and return the last element of the dictionary.
- popped_item = dict1.pop(‘key2’)
- print(popped_item)
Advantages of using a dictionary in Python
Dictionaries have several advantages over other data types:
- They are easy to use and understand.
- They are efficient for storing and retrieving data.
- They are mutable, which means they can be changed after they have been created.
- However, there are also some disadvantages to using dictionaries:
- They are unordered, which means that the order in which the key-value pairs are added to the dictionary is not preserved.
- They can only be used with immutable data types (such as strings, numbers, and tuples).
