By Komal Gupta 
In Python, min() and max() are built-in functions that return the smallest and largest value from a list, another iterable, or a set of separate arguments. They work on numbers, strings, and any values that can be compared with each other.
Both functions take the same arguments: an iterable or several values, an optional key function that changes how items are compared, and an optional default for empty iterables. This lesson shows how to use each form.
What Do the min() and max() Functions Do in Python?
min() returns the smallest value and max() returns the largest value from the values you pass in.
# 1. A list of exam scores
scores = [67, 91, 54, 88]
# 2. Smallest and largest
print(min(scores)) # Outputs: 54
print(max(scores)) # Outputs: 91
How to Use the Max Function in Python
1) Max of a List
Pass a list (or any iterable) as a single argument and max() returns its largest element.
daily_sales = [1240, 980, 1675, 1420]
print(max(daily_sales)) # Outputs: 1675
2) Max of Several Arguments
Pass two or more separate values and max() compares them directly. This form is common for clamping a number to a lower limit.
print(max(37, 12, 58)) # Outputs: 58
balance = -45
print(max(balance, 0)) # Outputs: 0
3) Max with the key Argument
The key argument takes a function, and max() compares the items by that function's result instead of the items themselves. The return value is the original item, not the key result.
usernames = ["kai", "alexandra", "meera"]
print(max(usernames, key=len)) # Outputs: alexandra
4) Max of Strings
With strings, max() compares alphabetically by Unicode code point, so "zoe" is greater than "adam". Uppercase letters sort before lowercase ones.
names = ["adam", "zoe", "lena"]
print(max(names)) # Outputs: zoe
How to Use the Min Function in Python
The min() function accepts the same forms as max(): one iterable, several arguments, and an optional key.
ticket_prices = [49.99, 32.50, 75.00]
print(min(ticket_prices)) # Outputs: 32.5
print(min(18, 5, 92)) # Outputs: 5
print(min(["oslo", "rio", "ulm"], key=len)) # Outputs: rio
When two items tie under key, both functions return the first one they meet, so min(["rio", "ulm"], key=len) returns "rio".
Min and Max of an Empty List
Calling either function on an empty iterable raises a ValueError.
refunds = []
print(max(refunds))
# ValueError: max() arg is an empty sequence
The default argument returns a fallback value instead of raising the error. It only works with the single-iterable form.
refunds = []
print(max(refunds, default=0)) # Outputs: 0
When to Use min() and max() in Python
1) Finding an Extreme in Data
Use them to pull the highest score, the cheapest price, or the longest name out of a collection in one call. Both functions scan the values once, so they run in O(n) time.
2) Clamping a Number to a Range
Combining the two keeps a value inside fixed limits: max(low, min(value, high)).
volume = 130
clamped = max(0, min(volume, 100))
print(clamped) # Outputs: 100
3) Picking a Record by One Field
With key, they select a whole record based on a single field, such as the product with the highest price.
Examples of Using min() and max() in Python
1) Highest Value in a Dictionary
On a dictionary, the functions compare the keys. Pass dict.get as the key argument to compare by value instead.
page_views = {"home": 5120, "pricing": 1890, "docs": 7301}
print(max(page_views)) # Outputs: pricing
print(max(page_views, key=page_views.get)) # Outputs: docs
The first call returns "pricing" because it is alphabetically the largest key.
2) Cheapest Product in a List of Tuples
products = [("keyboard", 89.99), ("mouse", 24.50), ("monitor", 219.00)]
cheapest = min(products, key=lambda item: item[1])
print(cheapest) # Outputs: ('mouse', 24.5)
3) Temperature Range of a Week
temps = [18.4, 22.1, 16.9, 24.3, 20.0]
print(max(temps) - min(temps)) # Outputs: 7.400000000000002
print(round(max(temps) - min(temps), 1)) # Outputs: 7.4
The long decimal comes from floating-point arithmetic, so round() is used for display.
Learn More About min() and max()
The Index of the Min or Max Value
The functions return the value, not its position. Combine them with index() to get the position of the extreme.
laps = [72.4, 69.8, 71.1]
fastest = min(laps)
print(laps.index(fastest)) # Outputs: 1
Min and Max of Mixed Types
Values must be comparable with each other. Comparing a number with a string raises a TypeError.
print(max([3, "ten", 7]))
# TypeError: '>' not supported between instances of 'str' and 'int'
NumPy min and max for Arrays
For large numeric arrays, NumPy's np.min() and np.max() run the scan in compiled code, which is faster than the built-ins on plain lists.
import numpy as np
readings = np.array([412, 388, 405, 391])
print(np.min(readings)) # Outputs: 388
print(np.max(readings)) # Outputs: 412
Key Takeaways for min() and max() in Python
- Two forms - pass one iterable or several separate values; both functions accept the same arguments.
- key - compares items by a function's result but returns the original item.
- default - returns a fallback for an empty iterable instead of raising
ValueError. - Strings - compared alphabetically by Unicode code point, so case affects the order.
- Cost - one scan through the values, O(n) time, no sorting involved.
A common companion task is finding the most frequent value rather than the largest one. For that, read our lesson on the Python Counter and its most_common() method.