On 08/12/2011 03:47 AM, Alan Gauld wrote:
On 12/08/11 07:04, Emeka wrote:
Hello All,
I need help here, type(item) == [].__class__:. What is the idiomatic way
of doing it?
if type(item) == type([])...
or in this case
if type(item) == list...
But probably preferrable to using type is to use isinstance:
if isinstance(item, list)...
And even more preferable still is don't check the type at
all but just try the operation
try:
item.doSomething()
except AttributeError:
doSomethingElse(item)
But that isn't always appropriate.
def myflatten(my_data):
gut = []
for item in my_data:
if type(item) == [].__class__:
gut = gut + myflatten ( item)
else:
gut.append(item)
return gut
In this particular case you presumably want to be
able to use any iterable object as an argument.
So it might be better written as:
def myflatten(my_data):
gut = []
for item in my_data:
try:
iter(item) # test for iterability
gut = gut + myflatten(item)
except TypeError:
gut.append(item)
return gut
This is exactly the way I'd think about this problem. But I'd also
point out the differences between the three.
if type(x) == list
is the most concise way to express the original relationship.
if you want to be able to also handle any type that's derived from list,
use isinstance().
If you want to be able to handle any iterable, use the final form.
It'll work on lists and tuples, for simple examples. But beware that
when you iterate through strings, the individual characters are also
strings, and this function will fail with an error like:
RuntimeError: maximum recursion depth exceeded
--
DaveA
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