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# Quote: Daniel Rouse Jr. #
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# To me, this looks like an array. Is tuple just the #
# Python name for an array? #
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The problem with understanding Python collections is directly due to improper
naming.
First let's consider the sequence types "list" and "tuple". For the most part
lists and tuples are exactly the same. They are both containers for holding
values.
GvR wisely choose to borrow the English word "list" over the esoteric CS term
"array", but he /unwisely/ choose to borrow the maths term "tuple" over
something more self-documenting to describe what is basically an immutable list.
Even someone who has no programming experience could most probably intuit what
a "Python list" /is/. Everyone has made a grocery list, or a "to-do" list. The
transformation from a tangible object like: *a linear list of items written on
paper* to an intangible object like: *a Python list holding N objects* is not
very difficult fathom. HOWEVER, then along comes the "seemingly" innocent tuple
with fiery red hair and that devilish little grin intent on screwing up the
whole logical flea circus!
Now you may ask yourself:
WHAT THE HELL IS A TUPLE? AND WHERE DID THIS ESOTERIC TERM ORIGINATE!
And if you ask the oracle (aka: Google) you might get this answer:
*Google Said:* /"""In mathematics and computer science, a tuple is an ordered
list of elements. In set theory, an (ordered) n-tuple is a sequence (or ordered
list) of n elements, where n is a non-negative integer. """"/
Okay google, so a tuple is an /ordered set/ and a list is an /ordered
collection/, got it, (and thanks GvR for the mental overload!) however the
names fail to convey this VERY important piece of information
For the fix, it would seem logical to simply extend the term "list" in a manner
that will convey a "set" relationship. "DynamicList" and "StaticList" fit the
bill HOWEVER these terms are FAR to verbose to use on a daily basis! Now, we
could naively use "list" for an ordered collection, and "staticlist" for an
ordered set, HOWEVER even this is a foolish choice!
The final solution is NOT two different types with verbose names, NO, the
solution is ONE ordered collection type with a method to convert it into an
ordered set. Observe:
py> list = list()
py> list.extend([1,2,3])
[1,2,3]
py> list.append('logical')
[1,2,3,'logical']
py> staticList = list.freeze()
py> staticList[-1]
'logical'
py> staticList.append('error')
Traceback (most recent call last):
File "<pyshell#1>", line 1, in <module>
staticList.append('error')
AttributeError: 'StaticList' object has no attribute 'append'
*school-bell*
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