On 2007-07-26, George Sakkis <[EMAIL PROTECTED]> wrote:
> That's not the only problem; try a string element to see it
> break too. More importantly, do you *always* want to handle
> strings as iterables ?
>
> The best general way to do what you're trying to is pass
> is_iterable() as an optional ar
On Jul 26, 2:56 pm, Neil Cerutti <[EMAIL PROTECTED]> wrote:
> On 2007-07-26, Marc 'BlackJack' Rintsch <[EMAIL PROTECTED]> wrote:
>
>
>
> > On Thu, 26 Jul 2007 15:02:39 +, Neil Cerutti wrote:
>
> >> Based on the discussions in this thread (thanks all for your
> >> thoughts), I'm settling for:
>
On 2007-07-26, Marc 'BlackJack' Rintsch <[EMAIL PROTECTED]> wrote:
> On Thu, 26 Jul 2007 15:02:39 +, Neil Cerutti wrote:
>
>> Based on the discussions in this thread (thanks all for your
>> thoughts), I'm settling for:
>>
>> def is_iterable(obj):
>> try:
>> iter(obj).next()
>> return
On Thu, 26 Jul 2007 15:02:39 +, Neil Cerutti wrote:
> Based on the discussions in this thread (thanks all for your
> thoughts), I'm settling for:
>
> def is_iterable(obj):
> try:
> iter(obj).next()
> return True
> except TypeError:
> return False
> except KeyError:
> ret
Based on the discussions in this thread (thanks all for your
thoughts), I'm settling for:
def is_iterable(obj):
try:
iter(obj).next()
return True
except TypeError:
return False
except KeyError:
return False
The call to iter will fail for objects that don't support the
iterat
Neil Cerutti a écrit :
> def is_iterable(obj):
> try:
> iter(obj)
> return True
> except TypeError:
> return False
>
> Is there a better way?
The only other alternative I see is worse:
def iterable(obj):
# strings are iterable and don't have an __iter__ method.
Carsten Haese wrote:
> On Wed, 2007-07-25 at 19:26 +, Neil Cerutti wrote:
>> Speaking of the iter builtin function, is there an example of the
>> use of the optional sentinel object somewhere I could see?
>
> Example 1: If you use a DB-API module that doesn't support direct cursor
> iteration
On Wed, 25 Jul 2007 15:46:14 -0400, Carsten Haese wrote:
> On Wed, 2007-07-25 at 19:11 +, Marc 'BlackJack' Rintsch wrote:
>> And just calling `iter()` doesn't work either:
>>
>> In [72]: class A:
>>: def __getitem__(self, key):
>>: if key == 42:
>>:
On Jul 25, 3:26 pm, Neil Cerutti <[EMAIL PROTECTED]> wrote:
> Speaking of the iter builtin function, is there an example of the
> use of the optional sentinel object somewhere I could see?
# iterate over random numbers from 1 to 10; use 0 as a sentinel to
stop the iteration
for n in iter(lambda:r
On 2007-07-25, Carsten Haese <[EMAIL PROTECTED]> wrote:
> On Wed, 2007-07-25 at 19:26 +, Neil Cerutti wrote:
>> Speaking of the iter builtin function, is there an example of the
>> use of the optional sentinel object somewhere I could see?
>
> Example 1: If you use a DB-API module that doesn't
mapped(func, iterable):
for item in iterable:
try:
for it in flattened(item):
yield func(it)
except TypeError:
yield func(item)
I'd be more confortable excepting some sort of IterationError (or
using an is_iterable function, of course). I guess there's
Neil Cerutti <[EMAIL PROTECTED]> wrote:
> Speaking of the iter builtin function, is there an example of the
> use of the optional sentinel object somewhere I could see?
for line in iter(open('somefile.txt', 'r').readline, ''):
print line
--
http://mail.python.org/mailman/listinfo/python
On Wed, 2007-07-25 at 19:26 +, Neil Cerutti wrote:
> Speaking of the iter builtin function, is there an example of the
> use of the optional sentinel object somewhere I could see?
Example 1: If you use a DB-API module that doesn't support direct cursor
iteration with "for row in cursor", you c
On Wed, 2007-07-25 at 19:11 +, Marc 'BlackJack' Rintsch wrote:
> And just calling `iter()` doesn't work either:
>
> In [72]: class A:
>: def __getitem__(self, key):
>: if key == 42:
>: return 'answer'
>: raise KeyError
>:
That's not going to hold true for generator functions or iterators
that are implemented on sequences without '__iter__.' You might also
want to check for __getitem__. I'm not sure if there's a way to tell
if a function is a generator without actually calling it.
-Jeff
On 7/25/07, [EMAIL PROTEC
On 2007-07-25, [EMAIL PROTECTED] <[EMAIL PROTECTED]> wrote:
> You can use the built-in dir() function to determine whether or not
> the __iter__ method exists:
I think you might have to check for __getitem__, also, which may
support the sequence protocol.
> def is_iterable(thing):
> return '_
On Wed, 2007-07-25 at 11:58 -0700, [EMAIL PROTECTED] wrote:
> You can use the built-in dir() function to determine whether or not
> the __iter__ method exists:
>
> class Iterable(object):
> def __iter__(self):
> pass
>
> class NotIterable(object):
> pass
>
> def is_iterable(thing
On Wed, 25 Jul 2007 11:58:40 -0700, [EMAIL PROTECTED] wrote:
> You can use the built-in dir() function to determine whether or not
> the __iter__ method exists:
Doesn't work:
In [58]: is_iterable('hello')
Out[58]: False
But strings *are* iterable.
And just calling `iter()` doesn't work either:
You can use the built-in dir() function to determine whether or not
the __iter__ method exists:
class Iterable(object):
def __iter__(self):
pass
class NotIterable(object):
pass
def is_iterable(thing):
return '__iter__' in dir(thing)
print 'list is iterable = ', is_iterable(l
def is_iterable(obj):
try:
iter(obj)
return True
except TypeError:
return False
Is there a better way?
--
Neil Cerutti
--
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