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Python: Find the indices of all occurrences of a given item in a given list

Python Basic - 1: Exercise-109 with Solution

Write a Python program to find the indices of all occurrences of a given item in a given list.

Sample Solution-1:

Python Code:

def indices_in_list(nums_list, n):
           return [idx for idx, i in enumerate(nums_list) if i == n]
nums = [1,2,3,4,5,2]
print("Original list of numbers:",nums)
n = 2
print("Given Number",n)
print("Indices of all occurrences of the said item in the given list:")
print(indices_in_list(nums, n))
nums = [3,1,2,3,4,5,6,3,3]
print("\nOriginal list of numbers:",nums)
n = 3
print("Given Number",n)
print("Indices of all occurrences of the said item in the given list:")
print(indices_in_list(nums, n))
nums = [1,2,3,-4,5,2,-4]
print("\nOriginal list of numbers:",nums)
n = -4
print("Given Number",n)
print("Indices of all occurrences of the said item in the given list:")
print(indices_in_list(nums, n))
nums = [1,2,3,4,5,2]
print("\nOriginal list of numbers:",nums)
n = 7
print("Given Number",n)
print("Indices of all occurrences of the said item in the given list:")
print(indices_in_list(nums, n))

Sample Output:

Original list of numbers: [1, 2, 3, 4, 5, 2]
Given Number 2
Indices of all occurrences of the said item in the given list:
[1, 5]

Original list of numbers: [3, 1, 2, 3, 4, 5, 6, 3, 3]
Given Number 3
Indices of all occurrences of the said item in the given list:
[0, 3, 7, 8]

Original list of numbers: [1, 2, 3, -4, 5, 2, -4]
Given Number -4
Indices of all occurrences of the said item in the given list:
[3, 6]

Original list of numbers: [1, 2, 3, 4, 5, 2]
Given Number 7
Indices of all occurrences of the said item in the given list:
[]

Pictorial Presentation:

Python: Find the indices of all occurrences of a given item in a given list.
Python: Find the indices of all occurrences of a given item in a given list.

Flowchart:

Flowchart: Python - Find the indices of all occurrences of a given item in a given list.

Sample Solution-2:

Python Code:

from itertools import count
def indices_in_list(nums_list, n):
           return [(i) for i, j in zip(count(), nums_list) if j == n]
nums = [1,2,3,4,5,2]
print("Original list of numbers:",nums)
n = 2
print("Given Number",n)
print("Indices of all occurrences of the said item in the given list:")
print(indices_in_list(nums, n))
nums = [3,1,2,3,4,5,6,3,3]
print("\nOriginal list of numbers:",nums)
n = 3
print("Given Number",n)
print("Indices of all occurrences of the said item in the given list:")
print(indices_in_list(nums, n))
nums = [1,2,3,-4,5,2,-4]
print("\nOriginal list of numbers:",nums)
n = -4
print("Given Number",n)
print("Indices of all occurrences of the said item in the given list:")
print(indices_in_list(nums, n))
nums = [1,2,3,4,5,2]
print("\nOriginal list of numbers:",nums)
n = 7
print("Given Number",n)
print("Indices of all occurrences of the said item in the given list:")
print(indices_in_list(nums, n))

Sample Output:

Original list of numbers: [1, 2, 3, 4, 5, 2]
Given Number 2
Indices of all occurrences of the said item in the given list:
[1, 5]

Original list of numbers: [3, 1, 2, 3, 4, 5, 6, 3, 3]
Given Number 3
Indices of all occurrences of the said item in the given list:
[0, 3, 7, 8]

Original list of numbers: [1, 2, 3, -4, 5, 2, -4]
Given Number -4
Indices of all occurrences of the said item in the given list:
[3, 6]

Original list of numbers: [1, 2, 3, 4, 5, 2]
Given Number 7
Indices of all occurrences of the said item in the given list:
[]

Flowchart:

Flowchart: Python - Find the indices of all occurrences of a given item in a given list.

Sample Solution-3:

Python Code:

from more_itertools import locate
def indices_in_list(nums_list, n):
           return list(locate(nums_list, lambda x: x == n))
nums = [1,2,3,4,5,2]
print("Original list of numbers:",nums)
n = 2
print("Given Number",n)
print("Indices of all occurrences of the said item in the given list:")
print(indices_in_list(nums, n))
nums = [3,1,2,3,4,5,6,3,3]
print("\nOriginal list of numbers:",nums)
n = 3
print("Given Number",n)
print("Indices of all occurrences of the said item in the given list:")
print(indices_in_list(nums, n))
nums = [1,2,3,-4,5,2,-4]
print("\nOriginal list of numbers:",nums)
n = -4
print("Given Number",n)
print("Indices of all occurrences of the said item in the given list:")
print(indices_in_list(nums, n))
nums = [1,2,3,4,5,2]
print("\nOriginal list of numbers:",nums)
n = 7
print("Given Number",n)
print("Indices of all occurrences of the said item in the given list:")
print(indices_in_list(nums, n))

Sample Output:

Original list of numbers: [1, 2, 3, 4, 5, 2]
Given Number 2
Indices of all occurrences of the said item in the given list:
[1, 5]
Original list of numbers: [3, 1, 2, 3, 4, 5, 6, 3, 3]
Given Number 3
Indices of all occurrences of the said item in the given list:
[0, 3, 7, 8]
Original list of numbers: [1, 2, 3, -4, 5, 2, -4]
Given Number -4
Indices of all occurrences of the said item in the given list:
[3, 6]
Original list of numbers: [1, 2, 3, 4, 5, 2]
Given Number 7
Indices of all occurrences of the said item in the given list:
[]

Flowchart:

Flowchart: Python - Find the indices of all occurrences of a given item in a given list.

Python Code Editor:

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Previous:Write a Python program that takes three integers and check whether the sum of the last digit of first number and the last digit of second number equal to the last digit of third number.
Next: Write a Python program to remove the duplicate numbers from a given list of numbers.

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