How to find the maximum value in the Python list? You can find the maximum value in a list using various functions of Python. A list is a data structure that allows you to store and manipulate a collection of elements. Each element in the list has an index associated with it, starting from 0 for the first element. You can take multiple approaches to find the maximum value or the largest number in a list. Here, I will explain a few different ways to use built-in functions and custom code.

For example, by using the `max()`, `sort()`, `sorted()`, `reduce()`, `heap` queue, brute force approach, and tail recursive algorithm. In this article, I will explain how to find the maximum value in the list by using all these functions with examples.

## 1. Quick Examples of Finding Maximum Value in the List

If you are in a hurry, below are some quick examples of how to get the maximum value in the list.

``````
# Quick examples of finding maximum value in the list

# Initialize list
mylist = [5, 17, 32, 14, 10, 21]

# Example 1: Using max() function
# Get the maximum value in the list
max_value = max(mylist)

# Example 2: Find the maximum value
# Using sort() function
mylist.sort()
max_value = mylist[-1]

# Example 3: Using sort() function
mylist.sort(reverse=True)
max_value = mylist[0]

# Example 4: Find the maximum value
# Using sorted() function
sorted_list = sorted(mylist)
max_value = sorted_list[-1]

# Example 5: Using sorted() function with reverse
# param & get the maximum value
sorted_list = sorted(mylist, reverse=True)
max_value = sorted_list[0]

# Example 6: Get maximum value
# Using reduce() function
max_value = reduce(max, mylist)

# Example 7: Using reduce() function along with lambda
max_value = reduce(lambda x, y: x if x > y else y, mylist)

# Example 8: Find the maximum value
# Using heap queue
heapq.heapify(mylist)

# Example 9: Using brute force approach
max_value = float('-inf')
for num in mylist:
if num > max_value:
max_value = num

# Example 10: Using tail recursive algorithm
mylist = [5, 17, 32, 14, 10, 21]
def func(arr, max_=None):
if(max_ is None):
max_ = arr.pop()
current = arr.pop()
if(current > max_):
max_ = current
if(arr):
return func(arr, max_)
return max_
result = func(mylist)
``````

## 2. Find the Maximum Value of List Using max() Function

You can use the `max()` function to find the maximum value in a list. It takes an iterable(such as list, string, tuple, or, set) as its argument and returns the largest element from that iterable. For example, first, initialize a list called `mylist`, then use the `max()` function to find the maximum value in the list.

``````
# Initialize list
mylist = [5, 17, 32, 14, 10, 21]
print("Original list: ", mylist)

# Using max() function
# Get the maximum value in the list
max_value = max(mylist)
print("The largest number is:", max_value)
``````

Yields below output.

As you can see from the above largest value `32` has been returned.

You can also find the largest string in the list using `max()` function, that will compare the strings based on their lexicographical order (alphabetical order). For instance, the `max()` function is used to find the largest string in the list `mylist`. The strings are compared alphabetically, and the largest string is determined to be ‘`Python`‘.

``````
# Initialize list
print("Original list: ", mylist)

# Using max() to find the max value
max_value = max(mylist)
print("The largest string is:", max_value)
``````

Yields below output.

## 3. Find Maximum Value in List Using sort() Function

You can also find the maximum value in the list using the sort() function. For instance, initialize a list called `mylist` with some values, then use the `sort()` function to sort the list in ascending order. Finally, you can get the maximum value from the sorted list by using `[]` notation.

``````
# Initialize list
mylist = [5, 17, 32, 14, 10, 21]
print("Original list: ", mylist)

# Find maximum value
# Using sort() function
mylist.sort()
max_value = mylist[-1]
print("The largest number is:", max_value)

# Output:
# Original list:  [5, 17, 32, 14, 10, 21]
# The largest number is: 32
``````

Similarly, you can use the `sort()` function with `reverse` param to find the maximum value in a list. The `sort()` function is used to sort the list in ascending order/descending order. Set the `reverse=True` argument and pass it into `sort()`, it will sort the list in descending order. After sorting, the first element in the sorted list is a maximum element, which is accessed using indexing (`mylist[0]`).

``````
# Using sort() function with param reverse
# get the max value in a list
mylist.sort(reverse=True)
max_value = mylist[0]
print("The largest number is:", max_value)
``````

Yields the same output as above.

## 4. Find the Maximum Value in the List Using sorted() Function

You can also use the sorted() function to find the maximum value in a list. For example, First, initialize a list `mylist` with some values, then use the `sorted()` function to sort the list in ascending order. Finally, by retrieving the last element from the sorted list using `[]` notation, you can get the maximum value from a list.

``````
# Initialize list
mylist = [5, 17, 32, 14, 10, 21]
print("Original list: ", mylist)

# Find the maximum value
# Using sorted() function
sorted_list = sorted(mylist)
max_value = sorted_list[-1]
print("The largest number is:", max_value)
``````

In another way, you can find a maximum value in a list using the `sorted()` function with `reverse` parm. The `sorted()` function is used to create a new sorted list in descending order. Set the `reverse=True` argument and pass it into the `sorted()` function, it will sort the list in descending order. After sorting, the maximum value is the first element in the sorted list, which is accessed using indexing `sorted_list[0]`.

``````
# Using sorted() function
sorted_list = sorted(mylist, reverse=True)
max_value = sorted_list[0]
print("The largest number is:", max_value)
``````

Yields the same output as above.

## 5. Find the Maximum Value in the List Using reduce() Function

You can also find the maximum value from the list using the reduce(), which is a very useful function in functional programming and can also be used in Python. However, as you mentioned, it has been moved to the `functools` module.

In the below example, First, initialize a list `mylist` with some values. Use the `reduce()` function to find the maximum value in the list by passing the `max` function as the first argument and the `mylist` as the second argument. Assign the result to a variable called `max_value`.

``````
from functools import reduce

# Initialize list
mylist = [5, 17, 32, 14, 10, 21]
print("Original list: ", mylist)

# Get maximum value
# Using reduce() function
max_value = reduce(max, mylist)
print("The largest number is:", max_value)
``````

Alternatively, you can use the `reduce()` function along with the lambda function to find the maximum value from a list of numbers in Python. The `reduce()` function takes two arguments one is a lambda function and the other one is the given list.

The `lambda` function compares two numbers `x` and `y` and returns the larger of the two. The `reduce()` function applies this lambda function successively to the elements of the list until it reduces the list to a single value, which is the maximum value. Finally, you print “The largest number is: `32`” to the console.

``````
# Using reduce() function along with lambda
# get maximum value
max_value = reduce(lambda x, y: x if x > y else y, mylist)
print("The largest number is:", max_value)
``````

Yields the same output as above.

## 6. Find the Maximum Value in the List Using Heap Queue

You can also use the `heapq` module to implement a heap queue, which is a binary heap data structure that allows efficient access to the maximum or minimum element of the collection.

In the below example, you created a list of `mylist` and then used the `heapq.heapify()` function to convert the list into a heap. Then, you used the `heapq.nlargest()` function to get the largest element from the heap, which is `32`.

``````
import heapq

# Initialize list
mylist = [5, 17, 32, 14, 10, 21]
print("Original list: ", mylist)

# Find the maximum value
# Using heap queue
heapq.heapify(mylist)
max_value = heapq.nlargest(1, mylist)[0]
print("The largest number is:", max_value)
``````

Yields the same output as above.

## 7. Find the Maximum Value in the List Using Brute Force Approach

You can also find the maximum value in a list using a brute force approach, you can iterate over the list and compare each element with a variable that keeps track of the current maximum value.

In the below example, you initialize the `max_value` variable to negative infinity, which acts as a starting point. Then, you iterate over each element in the list `mylist`. If an element is greater than the current `max_value`, you update the `max_value` to that element. After iterating through all the elements, the `max_value` variable will hold the maximum value in the list.

``````
# Initialize list
mylist = [5, 17, 32, 14, 10, 21]
print("Original list: ", mylist)

# Using brute force approach
max_value = float('-inf')
for num in mylist:
if num > max_value:
max_value = num
print("The largest number is:", max_value)
``````

Yields the same output as above.

## 8. Using Tail Recursive Algorithm

You can also use the tail-recursive algorithm to find the maximum value in a list. The `func()` function takes two arguments: `arr`, which represents the list of numbers, and `max_`, which represents the maximum value found so far. The function starts by checking if the `max_` is None. If it is, the function initializes `max_` with the last element of the list using the pop() function. Next, the function pops the next element from the list and checks if it is greater than the current `max_`. If it is, the `max_` is updated to the new value.

``````
# Using tail recursive algorithm
mylist = [5, 17, 32, 14, 10, 21]

def func(arr, max_=None):
if(max_ is None):
max_ = arr.pop()
current = arr.pop()
if(current > max_):
max_ = current
if(arr):
return func(arr, max_)
return max_

result = func(mylist)
print(result)
``````

## Conclusion

In this article, I have explained how to find the maximum value in the list in Python by using the `max()`, `sort()`, `sorted()`, `reduce()`, `lambda`, heap queue, brute force approach, and tail recursive algorithm with examples.

Happy Learning !!