On 26 Jan 2006 15:40:47 -0800, "Murali" <[EMAIL PROTECTED]> wrote:
>In Python, dictionaries can have any hashable value as a string. In
>particular I can say
>
>d = {}
>d[(1,2)] = "Right"
>d["(1,2)"] = "Wrong"
>d["key"] = "test"
>
>In order to print "test" using % substitution I can say
>
>print "%(key)s" % d
>
>Is there a way to print "Right" using % substitution?
>
>print "%((1,2))s" % d
>
>gives me "Wrong". Is there any syntax which will allow me to get
>"Right" using % substitution?
You can modify the dict to try to convert the string to what it is
a source for, by eval, and try that as a key also, if you have no security
worries
about malevolent format strings:
>>> class D(dict):
... def __getitem__(self, key):
... print repr(key)
... if key in self: return dict.__getitem__(self, key)
... else: return self[eval(key)]
...
>>> d = D()
>>> d[(1,2)] = "Right"
>>> d["key"] = "test"
>>> print "%(key)s" % d
'key'
test
>>> print "%((1,2))s" % d
'(1,2)'
(1, 2)
Right
>>> d[123] = 'onetwothree'
>>> print "%(123)s" % d
'123'
123
onetwothree
Note recursive printing of converted key when the first one fails.
Of course if you _also_ define the string key for Wrong, that will
succeed, so it won't get converted to get Right:
>>> d["(1,2)"] = "Wrong"
>>> print "%((1,2))s" % d
'(1,2)'
Wrong
>>> d[(1,2)]
(1, 2)
'Right'
Do you have a real use case? Just curious.
Regards,
Bengt Richter
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