Author Dusty Phillips Reviewers

Stock = namedtuple("Stock", "symbol current high low")
stock = Stock("FB", 75.00, high=75.03, low=74.90)
The 
namedtuple
constructor accepts two arguments. The first is an identifier for the 
named tuple. The second is a string of space-separated attributes that the named 
tuple can have. The first attribute should be listed, followed by a space (or comma 
if you prefer), then the second attribute, then another space, and so on. The result is 
an object that can be called just like a normal class to instantiate other objects. The 
constructor must have exactly the right number of arguments that can be passed in 
as arguments or keyword arguments. As with normal objects, we can create as many 
instances of this "class" as we like, with different values for each.
The resulting 
namedtuple
can then be packed, unpacked, and otherwise treated like a 
normal tuple, but we can also access individual attributes on it as if it were an object:
>>> stock.high
75.03
>>> symbol, current, high, low = stock
>>> current
75.00
Remember that creating named tuples is a two-step process. 
First, use 
collections.namedtuple
to create a class, and 
then construct instances of that class.
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Python Data Structures
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Named tuples are perfect for many "data only" representations, but they are not ideal 
for all situations. Like tuples and strings, named tuples are immutable, so we cannot 
modify an attribute once it has been set. For example, the current value of
my company's stock has gone down since we started this discussion, but we can't
set the new value:
>>> stock.current = 74.98
Traceback (most recent call last):