Tuples Dictionaries

Tuples

Tuples is a sequence data type as well. We can keep different elements inside tuples. Tuples are a combination of different elements separated by a comma.

Tuples are also like a list but with a change that we can not change indivudual values inside a tuple. We can reference those individual elements though.

That makes a tuple immutable. Lists are mutable. Mutable means, we can change the individual elements.

You might have noticed that list uses square brackets to store elements. Tuples uses round brackets to store elements. Just don't be confused as of now with these bracket notations.

Just stick to the notation that list uses square brackets and tuples use round brackets.

We can change a list to a tuple by using the tuple() function

Dictionary

Dictionary stores different data types as a key value pair.

$$Key : Value$$

We usually don't use this way to create dictionaries as this confuses a lot of people as to why the syntax for creating dictionaries is so different.

If a character sequence in python has a string data type, then why Name, Age, Occupation, Excuse are not typed inside the quotes.

Well, a lot of these things will be cleared by the time we've reached the function chapter.

For now, let's look at an easier way which we all use to create dictionaries.

Now notice, no matter the way we chose to create the dictionary, notice in the output, that dictionaries have the curly brackets / braces and that the key value pairs are displayed with this notation

$$Key:Value$$

Now let's look at some useful operations with dictionaries to clear why this particular data type is so important.

Indexing with dictionaries

Individual values are stored inside a dictionaries as Values and we use some unique Keys to reference them.

$$Dictionary[Key] = Value$$

As you might have noticed, indexing with dictionaries is different from indexing in lists and tuples.

We can overwrite the indivudual values stored inside a dictionary. But let's first learn how to add values to a dictionary.

Now let's look at how we can delete individual elements of a dictionary.

Lets delete the value of the key "Salary" as Tickles clearly got offended with this question.

We will use the del keyword here.

Make sure you don't run the code cell containing del keyword twice, otherwise python will try to delete the value of key "Salary" again, which will cause error because we have already deleted it once.

Some useful methods inside dictionaries