How to Make Pairs in Python

In Python, we often need to work with collections of data. These collections may contain sets of values, which we refer to as pairs.

Working effectively with these pairs often involves performing tasks such as sorting, iterating, and manipulating them.

In Python, pairs can be created by various means, however, the most commonly used method is by using the built-in data type called tuples. Tuples are immutable which means they can’t be modified after they are created.

Step 1: Creating a Pair

Creating pairs in Python can be done using tuples. A tuple is created by placing all the elements, separated by commas, inside parentheses ().

# Creating a pair

pair = ('apple', 'banana')

print(pair)

This will output the pair:

('apple', 'banana')

Step 2: Accessing Elements in a Pair

You can access elements in a pair much like how you would with a list – using their index. Indexing starts at 0.

# Accessing elements in a pair

print(pair[0])

print(pair[1])

The output would be:

'apple'
'banana'

Step 3: Altering a Pair

As mentioned earlier, tuples are immutable, which means you cannot change an element of a pair once it is assigned. If you try to do so, you will encounter an error. For instance:

1	pair[1] = 'orange'

This would result in a TypeError stating ‘tuple’ object does not support item assignment.

Step 4: Iterating Over a Pair

Just like lists, you can iterate over tuples using a simple for loop.

# Iterating over a pair

for item in pair:

print(item)

This would output each item in the pair on a new line.

Step 5: Nesting Pairs

Pairs can contain other pairs (or lists), making them nested. You can access elements in nested pairs using their respective indices.

# Creating a nested pair

nested_pair = (('apple', 'banana'), ('grape', 'orange'))

print(nested_pair[0][0])

print(nested_pair[1][1])

This would output ‘apple’ and ‘orange’, respectively.

Complete Code