How to implement 2-D array using UserDict?

[jepler epler]

On Thu, 03 Aug 2000 04:29:58 GMT, Courageous
 <jkraska1 at san.rr.com> wrote:
>Sam Wun wrote:
>> 
>> I want to do something like:
>> 
>> import UserDict
>> dict = UserDict.UserDict()
>> dict["Section"]["key"] = "some value"

Strangely enough, I wrote code in another context which could serve you
here.

two_dee_dict = DefaultingDict({})
print two_dee_dict[0][1] # Exception, not defined
two_dee_dict[2][3] = 1
print two_dee_dict[2][3] # prints 1
print two_dee_dict[0] # prints {}
print two_dee_dict[2] # prints {3: 1}

Of course, you can also just write
x = {}
print x[0,1]  # Exception, not defined
x[2,3] = 1
print x[2,3]  # prints 1
print x       # prints {(2,3): 1}
------------------------------------------------------------------------
import UserDict, copy

class DefaultingDict(UserDict.UserDict):
	def __init__(self, default=None):
		self.default = default
		UserDict.UserDict.__init__(self)

	def __getitem__(self, key):
		try:
			return self.data[key]
		except:
			self.data[key] = copy.copy(self.default)
			return self.data[key]

def _test():
	x = DefaultingDict(0)
	x[1] = 1
	print x[0]
	print x[1]

	x = DefaultingDict([])
	print x[0]
	x[0].append("item")
	print x[0]
	x[0].append("item2")
	print x[0]

if __name__ == '__main__': _test()
------------------------------------------------------------------------