Python – Find Min Value and its index in List

In this tutorial, we will look at how to find the min value in a Python list and its corresponding index with the help of some examples.

How to get the minimum value in a list in Python?

A simple approach is to iterate through the list and keep track of the minimum value. Alternatively, you can also use the Python built-in min() function to find the minimum value in a list.

Let’s look at some of the different ways of finding the smallest value and its index in a list.

Loop through the list to find the minimum

Iterate through the list values and keep track of the min value. Here’s an example.

# create a list
ls = [3, 6, 7, 2, 1, 5]

# find min value using loop
min_val = ls[0]
for val in ls:
    if val < min_val:
        min_val = val
# display the min value
print(min_val)

Output:

1

Here, we iterate over each value in the list ls and keep track of the minimum value encountered in the variable min_val. After the loop finishes, the variable min_val stores the minimum value present in the list, 1.

You can use this method to get the index corresponding to the minimum value in the list as well. Use an additional variable to keep track of the current minimum value’s index.

# create a list
ls = [3, 6, 7, 2, 1, 5]

# find min value using loop
min_val = ls[0]
min_val_idx = 0
for i in range(len(ls)):
    if ls[i] < min_val:
        min_val = ls[i]
        min_val_idx = i
    
# display the min value
print(min_val)
# display its index
print(min_val_idx)

Output:

1
4

We get the minimum value and its index after the loop finishes. Here we iterate through the list via its index rather than the values. You can also use the enumerate() function to iterate through the index and value together.

Using min() to get the maximum value

You can also use the Python built-in min() function to get the min value in a list. The function returns the minimum value in the passed iterable (for example, list, tuple, etc.).

# create a list
ls = [3, 6, 7, 2, 1, 5]
# find min value
min(ls)

Output:

1

Using the min() function is simple and is just a single line code compared to the previous example.

You can use the list index() function to find the index corresponding to the minimum value (assuming you already know the minimum value).

# create a list
ls = [3, 6, 7, 2, 1, 5]

# find min value
min_val = min(ls)
# display the min value
print(min_val)
# display its index
print(ls.index(min_val))

Output:

1
4

We get the min value and its index in the list ls.

Note that the list index() function returns the index of the first occurrence of the passed value. If the min value occurs more than once in the list, you’ll only get the index of its first occurrence. You can use list comprehension to get all the indices of occurrence of the min value in the list.

# create a list
ls = [3, 6, 1, 2, 1, 5]

# find min value
min_val = min(ls)
print(min_val)
# find all indices corresponding to min val
min_val_idx = [i for i in range(len(ls)) if ls[i]==min_val]
print(min_val_idx)

Output:

1
[2, 4]

We get all the indices where the minimum value occurs in the list ls.

You might also be interested in –

• Find Mode of List in Python
• Python – Get median of a List