[Tutor] reduce with comprehension

[Alan Gauld]

> But in the general case can you do the same job as
> reduce in a list comprehension?
>>> def f(x, y):
...  return x + y
...
>>> tmp = [0]
>>> [f(x, y) for x in arr for y in [tmp[-1]] if tmp.append(f(x, y)) or 
>>> True][-1]
45

Let's try some more...

>>> def f(x, y):
...  return x*y
...
>>> tmp = [1]
>>> [f(x, y) for x in arr for y in [tmp[-1]] if tmp.append(f(x, y)) or 
>>> True][-1]
362880

OK, you've nearly convinced me that its possible but I think I still
prefer reduce()! :-)

Alan G.