Please note that almost all of the code above will not run if copied and pasted from the article. This is due to the wrong quote types being used, (probably courtesy of Word or similar). For example:

print(‘\nWithout Generators:’)
File "<ipython-input-1-41661fc54531>", line 1
    print(‘\nWithout Generators:’)
          ^
SyntaxError: invalid character in identifier  File "<ipython-input-1-41661fc54531>", line 1
    print(‘\nWithout Generators:’)
          ^
SyntaxError: invalid character in identifier

The correct quote types need to be used, e.g.:

print('\nWithout Generators:')

Without Generators:

or

print("\nWithout Generators:")

Without Generators: