On 02/12/2008, WM. <[EMAIL PROTECTED]> wrote:
> I recently asked a question about 'for' loops, expecting them to be similar
> to 'for-next' loops. I have looked at several on-line tutors but am still
> in the dark about what 'for' loops do.
> Does anyone have a plain English about the use of 'for' loops?
> Are 'while' loops the only way Python runs a sub-routine over & over?
I'm not sure exactly what you understand by a "for-next loop".
A for loop, essentially, iterates over a list [1]. e.g.
for fruit in ['apple', 'pear', 'banana', 'tomato']:
print fruit
The loop will set the variable 'fruit' to be 'apple', 'pear', etc. on
each pass through the loop.
If you just want to do something n times, the usual idiom is:
for i in range(n):
# do something, possibly involving i
range(n) is a function that will produce the list [0, 1, 2, ..., n-1].
Tutorials should cover this, so I'm not sure if I'm telling you
anything new. If there's something particular you're stuck on, ask
:-)
--
John.
[1] Technically, it iterates over an iterator, which you can think of
as an object that behaves like a list when you throw it at a for loop.
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