Respuesta :
Answer:
w = [i/10.0 for i in range(0,31,1)]
w[:] = [0.0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0]
w[:-2] = [0.0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8]
w[::5]= [0.0, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0]
w[2:-2:6] = [0.2, 0.8, 1.4, 2.0, 2.6]
Explanation:
List slicing (as it is called in python programming language ) is the creation of list by defining start, stop, and step parameters.
w = [i/10.0 for i in range(0,31,1)]
The line of code above create the list w with values 0, 0.1, 0.2, . . . , 3.
w[:] = [0.0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0]
since start, stop, and step parameters are not defined, the output returns all the list elements.
w[:-2] = [0.0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8]
w[:-2] since stop is -2, the output returns all the list elements from the beginning to just before the second to the last element.
w[::5]= [0.0, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0]
w[::5] since step is -2, the output returns the list elements at index 0, 5, 10, 15, 20, 25,30
w[2:-2:6] = [0.2, 0.8, 1.4, 2.0, 2.6]
the output returns the list elements from the element at index 2 to just before the second to the last element, using step size of 6.