Using the map() function to apply a function to a collection

A scalar function maps values from a domain to a range. When we look at the math.sqrt() function, as an example, we're looking at a mapping from the float value, x, to another float value, y = sqrt(x) such that . The domain is limited to positive values. The mapping can be done via a calculation or table interpolation.

The map() function expresses a similar concept; it maps one collection to another collection. It assures that a given function is used to map each individual item from the domain collection to the range collection—the ideal way to apply a built-in function to a collection of data.

Our first example involves parsing a block of text to get the sequence of numbers. Let's say we have the following chunk of text:

>>> text= """\
...       2      3      5      7     11     13     17     19     23     29 
...      31     37     41     43     47     53     59     61     67     71 
...      73     79     83     89...