Python: Find the indexes of numbers, below a given threshold

Last update on May 30 2025 11:49:48 (UTC/GMT +8 hours)

Indices Below Threshold

Write a Python program to find the indexes of numbers in a given list below a given threshold.

Input:
[(100,(0, 12, 45, 3, 4923, 322, 105, 29, 15, 39, 55))]
Output:
[0, 1, 2, 3, 7, 8, 9, 10]

Input:
[(10,(0, 12, 4, 3, 49, 9, 1, 5, 3))]
Output:
[0, 2, 3, 5, 6, 7, 8]

Visual Presentation:

Sample Solution:

Python Code:

# License: https://bit.ly/3oLErEI

# Define a function named 'test' that takes a list of numbers 'nums' and a threshold 'thresh' as input
def test(nums, thresh):
    # Use a list comprehension to find the indexes (i) of numbers in 'nums' that are below the given threshold 'thresh'
    return [i for i, n in enumerate(nums) if n < thresh]

# Create a list of numbers 'nums' with specific elements
nums = [0, 12, 45, 3, 4923, 322, 105, 29, 15, 39, 55]

# Assign a threshold value 'thresh' to the variable
thresh = 100

# Print the original list of numbers
print("Original list:")
print(nums)

# Print the threshold value
print("Threshold: ", thresh)

# Print a message indicating the operation to be performed on the list
print("Check the indexes of numbers of the said list below the given threshold:")

# Print the result of the test function applied to the 'nums' list with the given threshold value
print(test(nums, thresh))

# Create a different list of numbers 'nums' with specific elements
nums = [0, 12, 4, 3, 49, 9, 1, 5, 3]

# Assign a different threshold value 'thresh' to the variable
thresh = 10

# Print the original list of numbers
print("\nOriginal list:")
print(nums)

# Print the updated threshold value
print("Threshold: ", thresh)

# Print a message indicating the operation to be performed on the list
print("Check the indexes of numbers of the said list below the given threshold:")

# Print the result of the test function applied to the modified 'nums' list with the updated threshold value
print(test(nums, thresh))

Sample Output:

Original list:
[0, 12, 45, 3, 4923, 322, 105, 29, 15, 39, 55]
Threshold:  100
Check the indexes of numbers of the said list below the given threshold:
[0, 1, 2, 3, 7, 8, 9, 10]

Original list:
[0, 12, 4, 3, 49, 9, 1, 5, 3]
Threshold:  10
Check the indexes of numbers of the said list below the given threshold:
[0, 2, 3, 5, 6, 7, 8]

Flowchart:

For more Practice: Solve these Related Problems:

• Write a Python program to find and return the indices of all numbers in a list that are below a specified threshold.
• Write a Python program to iterate over a list using enumerate and output the positions of values less than a given threshold.
• Write a Python program to use list comprehension to collect indices of list elements that are below a provided limit.
• Write a Python program to implement a function that returns the indices of numbers meeting the threshold condition without using built-in functions.

Go to:

• Python Puzzles Exercises Home ↩
• Python Exercises Home ↩

Previous: Separate Parentheses Groups Perfectly.
Next: Test whether the given strings are palindromes.

Python Code Editor :

Have another way to solve this solution? Contribute your code (and comments) through Disqus.