Unpacking a Tuple in Python

Tuple unpacking is a powerful feature in Python that allows you to assign the values of a tuple to multiple variables in a single line. This technique makes your code more readable and efficient. In other words, It is a process where we extract values from a tuple and assign them to variables in a single step. This feature makes working with tuples more convenient and readable.

Tuple unpacking allows assigning values from a tuple directly to variables:

a, b, c = (100, 200, 300)
print(a)  
print(b)  
print(c)  

100
200
300

Key Rules:

• The number of variables on the left must match the number of elements in the tuple.
• If they do not match, Python raises a ValueError.
• Example: a, b = (100, 200, 300) # ValueError: too many values to unpack

Tuple Unpacking Techniques

1. Using _ for Unused Values

If we don’t need certain values, use _ as a throwaway variable or placeholder:

a, _, c = (100, 200, 300)
print(a)  
print(c)  

100
300

2. Using * for Variable-Length Unpacking

Python allows catching multiple elements using *, known as the extended unpacking technique:

a, *b = (1, 2, 3, 4, 5)
print(a)   
print(b)   

1
[2, 3, 4, 5]

3. Unpacking Nested Tuples

Tuples inside tuples can also be unpacked:

nested_tuple = (1, (2, 3), 4)
a, (b, c), d = nested_tuple
print(a)   
print(b)   
print(c)   
print(d)   

1
2
3
4

4. Tuple Unpacking with * in Function Arguments

a. using *args: When defining a function, *args allows passing multiple arguments as a tuple:

def add(*args):
    return sum(args)
print(add(1, 2, 3, 4))  

10

b. Using * for Argument Unpacking: Tuple unpacking can also be used when calling a function:

def add(a, b, c):
    return a + b + c
nums = (1, 2, 3)
print(add(*nums))