list, map and put of the Queue in the Tree Data Structure

[ndc85430]

map transforms the items in a iterable in some way. The iterable is passed as the second argument and a function that performs the transformation as the first. So, map calls the function on each of the items in the iterable producing a new one. It actually produces a generator, so list there turns that generator into a list.

The class in the example above adds nothing, other than a bit of noise.

>>> def double(x):
...     return 2 * x
... 
>>> values = [1, 7, 4, 10, 9]
>>> list(map(double, values))
[2, 14, 8, 20, 18]

A list comprehension does the same:

>>> [double(v) for v in values]
[2, 14, 8, 20, 18]