Intro to Python for Computer Science and Data Science: Learning to Program with AI, Big Data and The Cloud

Exercises

1. 11.1 What does the following code do?

   In [1]: def mystery(a, b):
      ...:     if b == 1:
      ...:        return a
      ...:     else:
      ...:        return a + mystery(a, b - 1)
      ...:
   
   In [2]: mystery(2, 10)
   Out[2]: ?????

2. 11.2 Find the logic error(s) in the following recursive function, and explain how to correct it (them). This function should find the sum of the values from 0 to n.

   In [3]: def sum(n):
      ...:     if n == 0:
      ...:        return 0
      ...:     else:
      ...:        return n + sum(n)
      ...:

3. 11.3 What does the following code do?

   In [4]: def mystery(a_array, size):
      ...:     if size == 1:
      ...:        return a_array[0]
      ...:     else:
      ...:        return a_array[size - 1] + mystery(a_array, size - 1)
      ...:
   In [5]: import numpy as np
   
   In [6]: numbers = np.arange(1, 11)
   
   In [7]: mystery(numbers, len(numbers)) ...