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 values from one collection to create another collection. It assures that the 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   97  101  103  107  109  113 
... 127...