Python arrays

Hello World 1. **Creating Arrays**: ```python import numpy as np # Create a 1D array arr1 = np.array([1, 2, 3, 4, 5]) print("1D array:", arr1) # Create a 2D array arr2 = np.array([[1, 2, 3], [4, 5, 6]]) print("2D array:\n", arr2) ``` 2. **Reshaping Arrays**: ```python # Reshape a 1D array to a 2D array reshaped_arr = arr1.reshape((1, 5)) print("Reshaped array:\n", reshaped_arr) ``` 3. **Array Arithmetic**: ```python # Element-wise addition arr_sum = arr1 + 5 print("Array after addition:", arr_sum) # Element-wise multiplication arr_product = arr1 * 2 print("Array after multiplication:", arr_product) ``` 4. **Accessing and Modifying Elements**: ```python # Access an element element = arr2[1, 2] # Access element in 2nd row, 3rd column print("Accessed element:", element) # Modify an element arr2[1, 2] = 10 print("Modified array:\n", arr2) ``` 5. **Slicing Arrays**: ```python # Slice a subarray sub_array = arr2[:, 1:3] # Get all rows, columns 1 to 2