Collections in Python

Collections can be described as bags/boxes of values or containers while sequences are data structures, especially associated with storage and groupings that can be accessed easily, most of the sequences are a member of collections.

Types of Collections

There are several different types of collections in Python. The collection data structure allows storing several objects with or without any certain order. You can add and remove stuff from a collection, and you can iterate over a collection. It’s a storage construct that allows you to collect things and perform operations on them.

Collections in Python are grouped into two types:

• Sequence

• Mapping

Python sequence

Sequences are a major data type arrangement in Python, with a concept of order, indexed numerically from 0, including string, list and tuple. Things always come out of them in the same order as they were put in. It’s worth noting that every sequence is a collection, but not every collection is a sequence.

Sequences have got two main features.

• The first one is the slicing operation, obtaining a certain number of items from a list.

• Indexing operation, allows a user to fetch a particular item or element in a list.

• Indexing also gives a chance to perform operations on particular items.

Python mapping

Mapping types collections, without a concept of order, indexed by keys, which include only one type, a dictionary. The ordering of items in sets is arbitrary (It’s technically not changeable). The ordering of keys and values in dictionaries is also random.

A collection is good because we can put more than one value in them and carry them all around in one convenient package. We have a bunch of values in a single ‘variable’.