splitting tables

[Skip Montanaro]

Re: splitting tables


robsom> ... I (still) don't like the "for in range()" way to build
robsom> loops.

That's needed only when you need a numeric index. Much of the time you can
just iterate over a container object:

for element in mylist:
print element

or

for key in mydict:
print (key, mydict[key])

Skip

[robsom]

Re: splitting tables

[color=blue]
> On Wed, 11 Feb 2004 00:44:18 +0000 (UTC), robsom wrote:[color=green]
>> I'm beginning to appreciate Python even though at first I hated this
>> indentation thing[/color]
>
> Yup. Just because something seems limiting doesn't mean it is.[/color]

Right, I'm just saying that I was used to indent when I wanted and what I
wanted and that I missed the "closing instruction"
But, to be fair, I've adapted much faster than I thought. Just a matter of
getting used to it.
[color=blue]
> The "for index in range( size )" is mostly recommended as a way to loop
> over a list; range( size ) will elegantly generate a sequence of indices
> into a list of size "size".
>
> What is it you don't like?[/color]

well, I just think that a kind of sintax like: for i=x to y
is much more intuitive and easy to use. It caused me a lot of errors,
particularly in the beginning because I wasn't getting the values I
wanted for the index. Again is probably just a matter of getting used to
it.
[color=blue]
> Because somewhere earlier in that code you must have imported the name
> 'split' into the base namespace. It's not there to begin with (and
> importing it is needlessly polluting the base namespace).
> They're two different functions. One is a method of string objects, one
> is a function you've imported from somewhere. (This confusion is partly
> why importing symbols into the base namespace is a bad idea.)[/color]

in fact there is an import string * instruction at the beginning.
ok, so you suggest using the method because it results in a faster code?
thanks

R

[Ben Finney]

Re: splitting tables

On Thu, 12 Feb 2004 00:56:22 +0000 (UTC), robsom wrote:[color=blue][color=green]
>> On Wed, 11 Feb 2004 00:44:18 +0000 (UTC), robsom wrote:[color=darkred]
>>> [why do str.split() and split(str) both work?][/color]
>> Because somewhere earlier in that code you must have imported the name
>> 'split' into the base namespace. It's not there to begin with (and
>> importing it is needlessly polluting the base namespace).[/color]
>
> in fact there is an import string * instruction at the beginning.[/color]

Yes, the "from module import *" is a deprecated usage; it pollutes the
base namespace, which leads to confusions like this and others.

The recommended way is to:

import module

module.function ()

So, in your case, this would be:

import string

string.split( str )

Then it becomes clear in each instance that the "split" function comes
from the "string" module, and not some other arbitrary module.
[color=blue][color=green][color=darkred]
>>> [are they the same function?][/color]
>> They're two different functions. One is a method of string objects,
>> one is a function you've imported from somewhere. (This confusion is
>> partly why importing symbols into the base namespace is a bad idea.)[/color]
>
> ok, so you suggest using the method because it results in a faster
> code?[/color]

No, I recommend using the method because it's already part of the string
objects, and results in clearer code.

--
\ "It ain't so much the things we don't know that get us in |
`\ trouble. It's the things we know that ain't so." -- Artemus |
_o__) Ward (1834-67), U.S. journalist |
Ben Finney <http://bignose.squidly .org/>

[John J. Lee]

Re: splitting tables

Skip Montanaro <skip@pobox.com > writes:
[color=blue]
> robsom> ... I (still) don't like the "for in range()" way to build
> robsom> loops.
>
> That's needed only when you need a numeric index. Much of the time you can
> just iterate over a container object:
>
> for element in mylist:
> print element
>
> or
>
> for key in mydict:
> print (key, mydict[key])[/color]

also (Python 2.3):

for index, element in enumerate(mylis t):
# blah, blah


John