In Python, there are two important concepts to grasp before delving into tuples and dictionaries: sequence types and mutability. Sequence types allow the storage of multiple values that can be browsed sequentially, while mutability refers to the ability of data to be freely changed during program execution. In this section, we will explore these concepts and shed light on the significance of immutable sequence types using the example of tuples.
Sequence Types
A sequence type in Python is a data type that can store more than one value, allowing sequential access to its elements. The for
loop is a useful tool designed to iterate through sequences, making it possible to scan the elements one by one. While lists are a well-known example of a Python sequence, there are other noteworthy sequence types that we will explore.
Mutability
Mutability defines whether a Python data type can be modified freely during program execution. There are two categories of Python data based on mutability: mutable and immutable.
Mutable data can be updated at any time, allowing modifications in its current position. For example, the list data type is mutable, enabling operations such as appending elements using the list.append() method. You can freely add or remove elements from a list.
In contrast, immutable data cannot be modified directly. Consider an immutable list: you can assign values and read them, but appending or removing elements is not possible. To perform such operations, you would need to create a new list from scratch, including all the existing elements along with the new element.
Introduction to Tuples
Now, let's focus on tuples, which are an example of an immutable sequence type in Python. Although tuples behave similarly to lists, they cannot be modified in its current position.
Being immutable means that once a tuple is defined, its elements cannot be changed. However, you can access individual elements of a tuple and perform operations on them. Tuples are created using parentheses and can contain different types of data.
Creating tuples is a fundamental aspect of working with immutable data in Python. By understanding the syntax and techniques for tuple creation, you can effectively utilize tuples in various programming scenarios. Whether it's initializing values, grouping related data, or returning multiple values from a function, tuples offer a versatile solution.