The simplest option to initialize a list with $N$ occurrences of a given value in Python is to use the repetition operator (*):

>>> myList=[2]*5
>>> myList
[2, 2, 2, 2, 2]

To create a list initialized with $N$ occurrences of a given value in Python, you can use the following methods:

1. Using the Repetition Operator

value = 42  # Replace with your desired value
N = 10      # Replace with the number of occurrences
result = [value] * N
print(result)

This creates a list with $N$ references to the same value.

2. Using a List Comprehension

value = 42
N = 10
result = [value for _ in range(N)]
print(result)

This also creates a list with $N$ occurrences, and it can be useful when the value needs to be dynamically calculated.

3. Using the list Constructor with repeat from itertools

from itertools import repeat

value = 42
N = 10
result = list(repeat(value, N))
print(result)

This approach is useful for large lists since repeat is lazy and doesn't create intermediate lists.

Important Note:

• If the value is a mutable object (e.g., a list or dictionary), using * will create $N$ references to the same object, not $N$ independent copies. Use the list comprehension method to ensure independent copies if needed:

value = [42]
N = 3
result = [[42] for _ in range(N)]  # Ensures separate lists
print(result)