Initializing with the correct type

[szabi]

aine_canby at yahoo.com írta:
> Hi all,
>
> I'm new to Python and I'm just wordering if my approch is correct.
> Here's an example. I'm making sure that the length and types are
> correct. This is in case I use such a class and accidently pass it the
> wrong object.
>
> class Funkt:
> 	'Funkt Class'
>
> 	def __init__(self, L):
> 		'Constructer, accepts a list L of ints, which is 1 or listLength in
> length'
> 		if len(L) not in (1,listLength):
> 			errorString = "Format Error: L must be 1"
> 			if listLength != 1:
> 				errorString += " or "+str(listLength)
> 			errorString += " in Length"
> 			raise FormatError,errorString
> 		for i in L:
> 			if type(i) is not int:
> 				raise FormatError, "L must contain ints"

if you need something for holding only ints, you could use the array
module:
>>> import array
>>> a = array.array('i')
>>> a.append(10)
>>> a.append('foo')
Traceback (most recent call last):
  File "<stdin>", line 1, in ?
TypeError: an integer is required
>>> type(a)
<type 'array.array'>
>>>

Szabi