How to Create an Empty List with a Predefined Size in Python?

Creating an Empty List with a Specified Size in Python

When attempting to assign values to an empty list created with xs = list(), you may encounter an IndexError due to incomplete initialization. To resolve this issue, it's necessary to assign None to the list elements to reserve the desired size.

Creating an Empty List of 10 Elements:

xs = [None] * 10

Assigning Values to Specific List Elements:

To assign a value to a specific element in the list, use the following syntax:

xs[index] = value

Example:

xs[1] = 5
print(xs)  # Result: [None, 5, None, None, None, None, None, None, None, None]

Alternative List Creation Methods:

• range(): Creates a list containing elements from 0 to the specified number minus one. For example:

xs = range(10)
print(xs)  # Result: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]

• List Comprehensions: Allows for concise list creation. For example:

xs = [x**2 for x in range(9)]
print(xs)  # Result: [0, 1, 4, 9, 16, 25, 36, 49, 64]

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