Python: Get a list with n elements removed from the left, right

Last update on April 19 2025 13:00:48 (UTC/GMT +8 hours)

Remove N Elements from Sides

Write a Python program to get a list with n elements removed from the left and right.

Removed from the left:

Use slice notation to remove the specified number of elements from the left.
Omit the last argument, n, to use a default value of 1.

Removed from the right:

Returns a list with n elements removed from the right.

Use slice notation to remove the specified number of elements from the right.
Omit the last argument, n, to use a default value of 1.

Sample Solution:

Python Code:

# Define a function named 'drop_left_right' that removes elements from the left and right of a list.
# It takes a list 'a' and an optional parameter 'n' specifying the number of elements to remove from both sides.
def drop_left_right(a, n=1):
    # Return a tuple of two lists: elements from index 'n' to the end and elements from the beginning to 'n' from the original list 'a'.
    return a[n:], a[:-n]

# Create a sample list 'nums' with integer elements.
nums = [1, 2, 3]
# Print the original list elements.
print("Original list elements:")
print(nums)
# Use the 'drop_left_right' function to remove 1 element from the left of the list and store the results in 'result'.
result = drop_left_right(nums)
# Print the list with 1 element removed from the left.
print("Remove 1 element from the left of the said list:")
print(result[0])
# Print the list with 1 element removed from the right.
print("Remove 1 element from the right of the said list:")
print(result[1])

# Create another sample list 'nums' with integer elements.
nums = [1, 2, 3, 4]
# Print the original list elements.
print("\nOriginal list elements:")
print(nums)
# Use the 'drop_left_right' function to remove 2 elements from the left of the list and store the results in 'result'.
result = drop_left_right(nums, 2)
# Print the list with 2 elements removed from the left.
print("Remove 2 elements from the left of the said list:")
print(result[0])
# Print the list with 2 elements removed from the right.
print("Remove 2 elements from the right of the said list:")
print(result[1])

# Create another sample list 'nums' with integer elements.
nums = [1, 2, 3, 4, 5, 6]
# Print the original list elements.
print("\nOriginal list elements:")
print(nums)
# Use the 'drop_left_right' function without specifying 'n' to remove 1 element from both left and right.
result = drop_left_right(nums)
# Print the list with 1 element removed from both left and right.
print("Remove 1 element from both left and right of the said list:")
print(result[0])
print("Remove 1 element from both left and right of the said list:")
print(result[1])

Sample Output:

Original list elements:
[1, 2, 3]
Remove 1 element from left of the said list:
[2, 3]
Remove 1 element from right of the said list:
[1, 2]

Original list elements:
[1, 2, 3, 4]
Remove 2 elements from left of the said list:
[3, 4]
Remove 2 elements from right of the said list:
[1, 2]

Original list elements:
[1, 2, 3, 4, 5, 6]
Remove 7 elements from left of the said list:
[2, 3, 4, 5, 6]
Remove 7 elements from right of the said list:
[1, 2, 3, 4, 5]

Flowchart:

For more Practice: Solve these Related Problems:

Write a Python program to remove n elements from both the left and right ends of a list.
Write a Python program to remove a specified percentage of elements from both ends of a list.
Write a Python program to remove n elements from the start and a different number m from the end of a list.
Write a Python program to remove n elements from each side and return an empty list if n exceeds half the list's length.

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