How Can I Replace Values in Lists with Python Based on Conditions?

Replace Values in Lists with Python

In Python, we may encounter situations where we need to replace specific values in lists based on certain conditions. One efficient way to achieve this is by utilizing list comprehensions.

Suppose we have a list items and want to replace all even numbers with None. We can employ the following list comprehension:

<code class="python">new_items = [x if x % 2 else None for x in items]</code>

This comprehension constructs a new list where each element x from items is assigned a value of None if x is even (i.e., x % 2 evaluates to 0), otherwise, x remains unchanged.

For example, consider the list [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10]. If we apply the above comprehension, it will return: [None, 1, None, 3, None, 5, None, 7, None, 9 ,None].

It's worth noting that modifying the original list in-place (e.g., within a loop) offers no time savings compared to creating a new list with a list comprehension.

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