Python reduce explanation

Question

I\'m not able to understand the following code segment:

>>> lot = ((1, 2), (3, 4), (5,))
>>> reduce(lambda t1, t2: t1 + t2, lot)
(1, 2, 3,          


        

Answer 1

reduce(...) reduce(function, sequence[, initial]) -> value

Apply a function of two arguments cumulatively to the items of a sequence,
from left to right, so as to reduce the sequence to a single value.
For example, reduce(lambda x, y: x+y, ((1, 2), (3, 4), (5))) calculates
(((1+2)+(3+4))+5).  If initial is present, it is placed before the items
of the sequence in the calculation, and serves as a default when the
sequence is empty.