How to Check if a List is Sorted in Python?

Determining List Order with Pythonic Precision

Is there a Pythonic way to determine if a list is sorted in ascending or descending order?

Imagine having a list of timestamps from messages and needing to verify whether they appeared in the correct sequence. Wouldn't it be convenient to have a built-in method that simplifies this task?

Introducing the Pythonic Solution:

Instead of relying on custom code, Python offers a concise and elegant solution:

all(l[i] <= l[i+1] for i in range(len(l) - 1))

This one-liner checks if each element in the list is less than or equal to the next, effectively verifying ascending order. If you require descending order, simply replace "<=" with ">=" in the expression.

Practical Application:

To illustrate its usefulness, let's evaluate the list of timestamps provided:

listtimestamps = [1, 2, 3, 5, 6, 7]

Using the Pythonic solution, we can ascertain whether the timestamps are in ascending order:

is_sorted = all(l[i] <= l[i+1] for i in range(len(listtimestamps) - 1))
print(is_sorted)  # Output: True

This snippet effectively demonstrates the practicality and efficiency of this Pythonic approach for verifying list order.

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