Unzipping a zipped sequence

We can insert zip() mapping can be inverted. We'll look at several ways to unzip a collection of tuples.

The first way is something we've seen many times: we can use a generator function to unzip a sequence of tuples. For example, assume that the following pairs are a sequence object with two-tuples:

p0= (x[0] for x in pairs)
p1= (x[1] for x in pairs)  

This will create two sequences. The p0 sequence has the first element of each two-tuple; the p1 sequence has the second element of each two-tuple.

Under some circumstances, we can use the multiple assignment of a for loop to decompose the tuples. The following is an example that computes the sum of the products:

sum(p0*p1 for for p0, p1 in pairs)  

We used the for statement to decompose each two-tuple into p0 and p1.