## How do I find the Index of the smallest number in an array in python if I have multiple smallest numbers and want both indexes?

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I have an array in which I want to find the index of the smallest elements. I have tried the following method:

```distance = [2,3,2,5,4,7,6]

a = distance.index(min(distance))
```

This returns 0, which is the index of the first smallest distance. However, I want to find all such instances, 0 and 2. How can I do this in Python?

You may enumerate array elements and extract their indexes if the condition holds:

```min_value = min(distance)
[i for i,n in enumerate(distance) if n==min_value]
#[0,2]
```

Find K smallest and largest values and its indices in a numpy array , To find the maximum and minimum value in an array you can use numpy argmax and argmin function. These two functions( argmax and argmin )� Python Program to find the Smallest Number in a List Example 2. This python program is the same as above. But this time, we are allowing the user to enter the length of a List.

Use np.where to get all the indexes that match a given value:

```import numpy as np

distance = np.array([2,3,2,5,4,7,6])

np.where(distance == np.min(distance))

Out: array([0, 2])
```

Numpy outperforms other methods as the size of the array grows:

##### Results of TimeIt comparison test, adapted from Yannic Hamann's code below
```                     Length of Array x 7
Method               1       10      20      50     100    1000
Sorted Enumerate     2.47  16.291  33.643
List Comprehension  1.058   4.745   8.843  24.792
Numpy               5.212   5.562   5.931    6.22  6.441  6.055
Defaultdict         2.376   9.061  16.116  39.299
``` Python - Find the indices for k Smallest elements, Sometimes, while working with Python lists, we can have a problem in which we This task can occur in many domains such as web development and while Let's discuss a certain way to find indices of K smallest elements in list. If you like GeeksforGeeks and would like to contribute, you can also write� To find largest and smallest number in a list. Approach : Read input number asking for length of the list using input() or raw_input(). Initialise an empty list lst = []. Read each number using a

Surprisingly the `numpy` answer seems to be the slowest.

Update: Depends on the size of the input list.

```import numpy as np
import timeit
from collections import defaultdict

se = sorted(enumerate(distance), key=lambda x: x)
smallest_numb = se  # careful exceptions when list is empty
return [x for x in se if smallest_numb == x]
# t1 = 1.8322973089525476

def pythonic_way(distance):
min_value = min(distance)
return [i for i, n in enumerate(distance) if n == min_value]
# t2 = 0.8458914929069579

def fastest_dont_even_have_to_measure(np_distance):
# np_distance = np.array([2, 3, 2, 5, 4, 7, 6])
min_v = np.min(np_distance)
return np.where(np_distance == min_v)
# t3 = 4.247801031917334

d = defaultdict(list)  # a dictionary where every value is a list by default

for idx, num in enumerate(distance):
d[num].append(idx)  # for each number append the value of the index

return d.get(min(distance))
# t4 = 1.8876687170704827

def wrapper(func, *args, **kwargs):
def wrapped():
return func(*args, **kwargs)
return wrapped

distance = [2, 3, 2, 5, 4, 7, 6]

t2 = wrapper(pythonic_way, distance)
t3 = wrapper(fastest_dont_even_have_to_measure, np.array(distance))

print(timeit.timeit(t1))
print(timeit.timeit(t2))
print(timeit.timeit(t3))
print(timeit.timeit(t4))
```

numpy.amin(), Python's numpy module provides a function to get the minimum If it's provided then it will return for array of min values along the axis i.e. Get the array of indices of minimum value in numpy array using numpy.where() i.e. Tuple of arrays returned : (array([0, 2], dtype=int32), array([0, 2], dtype=int32)). C Program to Find Smallest Number in an Array. In this C Program to find the smallest number in an array, we declared 1 One Dimensional Arrays a[] of size 10.We also declared i to iterate the Array elements, the Smallest variable to hold the smallest element in an Array.

We can use an interim dict to store indices of the list and then just fetch the minimum value of distance from it. We will also use a simple for-loop here so that you can understand what is happening step by step.

```from collections import defaultdict

d = defaultdict(list) # a dictionary where every value is a list by default

for idx, num in enumerate(distance):
d[num].append(idx) # for each number append the value of the index

d.get(min(distance)) # fetch the indices of the min number from our dict

[0, 2]
```

How do I find the indices of the maximum (or minimum) value of my , Learn more about maximum, minimum, max, min, index, array, matrix, find, I would like to know how to find the indices of just the maximum (or minimum) value. The "min" and "max" functions in MATLAB return the index of the minimum and maximum values, respectively, I got two indices, both have the same value. Given a list of numbers, the task is to write a Python program to find the smallest number in given list. Examples: Input : list1 = [10, 20, 4] Output : 4 Input : list2 = [20, 10, 20, 1, 100] Output : 1

You can also do the following `list comprehension`

```distance = [2,3,2,5,4,7,6]
min_distance = min(distance)
[index for index, val in enumerate(distance) if val == min_distance]
>>> [0, 2]
```

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Sorting Arrays, This section covers algorithms related to sorting values in NumPy arrays. science courses: if you've ever taken one, you probably have had dreams (or, For example, a simple selection sort repeatedly finds the minimum value from a list, [1 2 3 4 5]. A related function is argsort , which instead returns the indices of the� As our array arr is a flat 1D array, so returned tuple will contain only one array of indices and contents of the returned array result are, [ 4 7 11] Get the first index of element with value 15,

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• when you compare distance of the type `numpy.ndarray` with an integer it always evaluates the FULL array.