On 11/17/07, bob gailer ([EMAIL PROTECTED]) wrote:
>Michael wrote:
>> Hi All
>>
>> This has probably been asked before but can I get some clarification on
>> why Python does not have a repeat...until statement, and does that mean
>> repeat...until is bad practice? I was trying to get Python on the
>> standard langauge list for my state secondary school system but they say
>> a langauge must have a test last structure in it to be considered.
>>
>That rules out FORTRAN!
>
>And I would point out (as one of us already did):
>
>while True:
> blahblah
> if condition: break
>
>Is a test-last structure.
If one considers the "repeat" statement to have an _implied_ truthfulness there
is even less difference _except_ for the nesting syntax which IMO is arbitrary
and therefore moot.
repeat [while true]
perform task
until [proven false by] condition
or
do [while true]
blah blah blah
VS the explicitly stated
>while True:
> blahblah
> if condition: break
Python is a very rich language and provides a great deal of flexibility, even
with this single flow-control statement i.e.
while [state | condition] maintains truthfulness:
perform task [intrinsically modify state | argument(s)]
[test argument(s) & exit | modify state]
Python is a modern and full-featured language. The test of its sutability
should be based upon its clarity and capability rather than an arbitrary
syntactical (sp?) construct.
Can the language clearly perform looping constructs: yes, in many ways.
Does the language have a reasonable level of flow-control: yes.
...
I could see a language like PHP being excluded because of its dependence upon
environment. But if I were to teach a language to a student, Python would
probably be one of my first choices as opposed to C/Java/Perl/VB/AppleScript
and such.
Ultimately, what is the objective of the programming programme? Is it to teach
students to consider application development at a high-level or incumber them
with unnecessary syntax at a low level i.e.
def some_variable as some_type
test some_variable then
...
end test
IMO, the def, then and end are unnecessary cluter; totally superfluious!
Personally, I would rather my students (if I had any) be less incumbered with
"verbosity" and more focussed on planning and understanding. Letting the
language work for them rather than enslaving them.
"When the only tool you have is a hammer, all of your problems start looking
like nails" is a favorite quote of mine (unknown origin). Python is one heck of
a hammer to have in the bag.
Scott
PS. Interesting thing about Python: in minutes a student could be working with
the language i.e. 'Hello world', and understand it. Within days they can be
writing functional code with reasonable complexity. The kicker is, the language
is deep enough that new approaches can still appear many months and even years
of regular use. Not only is it tasty, it's nutritious too ;^)
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