[Python] How to efficiently create an array from a list?

I have a list containing 2D arrays with same number of rows but different number of columns. I need to create a padded array of arrays with same shape. My current code is below but due to the for loop, the code is very inefficient for large lists. How can I create a padded array more efficiently?

MWE:

import numpy as np


list_length = 552

# Irregular shape arrays in the list
# list_with_irregular_arrays[0].shape = (10, 40)
# .
# .
# list_with_irregular_arrays[100].shape = (10, 60)
list_with_irregular_arrays = [np.random.rand(10, np.random.randint(30, 70)) for _ in range(list_length)] # NOTE: Only to create example data

# Create padded array
num_rows = 10
num_cols = max(arr.shape[1] for arr in list_with_irregular_arrays)
padded_array = np.full((list_length, num_rows, num_cols), np.nan, dtype=np.float32)

for i in range(list_length):
arr = list_with_irregular_arrays
padded_array[i, :, :arr.shape[1]] = arr

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