Python min() Function

Spread the love

The min() function returns the smallest item in an iterable or the smallest of two or more arguments.


The syntax of the min() function is as follows:

min(arg1, arg2, *args[, key])
min(iterable[, key])

Here, arg1 and arg2 are two arguments among which you want to find the minimum, while *args allows comparison among more than two items. The key parameter is optional and specifies a one-argument ordering function like that used for list.sort(). The second form is used when you have an iterable such as a list or a tuple.


  • *arg1, arg2, args: Non-keyword variable-length argument list.
  • iterable: An iterable such as a list, tuple, set, etc.
  • key (optional): A function that serves as a key for the sort comparison.

Return Value:

The min() function returns the smallest item from the iterable or the smallest of the provided arguments.

Usage Across Data Types

Numerical Values

When used with numbers, min() will return the smallest numerical value.

print(min(4, 1, 17, 3))  # Output: 1
print(min([45, 32, 89, 2]))  # Output: 2


For strings, min() compares the values using alphabetical order.

print(min("apple", "banana", "cherry"))  # Output: 'apple'

Tuples and Lists

It can also compare complex iterables, like lists of tuples, based on the first element in the tuples, then the second, and so forth.

print(min([("apple", 2), ("orange", 3), ("banana", 1)]))  # Output: ('apple', 2)

Custom Objects

When dealing with custom objects, you can use min() with the key parameter to specify the attribute by which to compare the objects.

class Car:
    def __init__(self, make, model, year, price):
        self.make = make
        self.model = model
        self.year = year
        self.price = price

cars = [
    Car("Toyota", "Corolla", 2020, 20000),
    Car("Honda", "Civic", 2019, 18000),
    Car("Ford", "Mustang", 2021, 26000)

cheapest_car = min(cars, key=lambda x: x.price)
print(cheapest_car.make)  # Output: 'Honda'

The Key Parameter

The key function is critical when working with complex data types as it allows customization of the comparison criteria.

students = [
    {'name': 'Alice', 'grade': 85},
    {'name': 'Bob', 'grade': 95},
    {'name': 'Charlie', 'grade': 78}

worst_grade = min(students, key=lambda x: x['grade'])
print(worst_grade['name'])  # Output: 'Charlie'

Error Handling in min()

Understanding how min() handles errors is crucial for robust code.

  • TypeError: Occurs when arguments are of different, non-comparable types.
  • ValueError: Arises when an empty iterable is passed.
    print(min([]))  # Raises ValueError
except ValueError as e:
    print(e)  # Output: 'min() arg is an empty sequence'

Real-World Applications

The min() function has a variety of practical uses:

1. Finding the Lowest Score

scores = [88, 92, 79, 93, 85]
print(f"The lowest score is: {min(scores)}")
# Output: The lowest score is: 79

2. Inventory Management

inventory = [
    {'item': 'Widget', 'quantity': 40},
    {'item': 'Gadget', 'quantity': 50},
    {'item': 'Doodad', 'quantity': 30}

lowest_stock = min(inventory, key=lambda x: x['quantity'])
print(f"Item with the lowest stock: {lowest_stock['item']}")
# Output: Item with the lowest stock: Doodad

3. Time Series Data

Finding the lowest value in a time series can indicate trends or trigger alerts.

temperatures = {'9AM': 72, '12PM': 76, '3PM': 78, '6PM': 73}
coldest_time_of_day = min(temperatures, key=temperatures.get)
print(f"Coolest time of day: {coldest_time_of_day}")
# Output: Coolest time of day: 9AM

4. Text Analysis

Determining the shortest word in a text can be part of a linguistic analysis.

words = ["Mountain", "Hill", "Lake", "River"]
print(f"The shortest word is: {min(words, key=len)}")
# Output: The shortest word is: Hill


The min() function in Python is a testament to the language’s capability to provide clear, concise, and powerful tools for programmers. Its ability to work across different data types, handle errors gracefully, and offer performance considerations, makes it a versatile and essential part of the Python standard library.

Leave a Reply