"sudhanshu gautam" <[email protected]> wrote
and setdefault used to set the value is side the dictionary if it does
not
lies inside the dictionary.
so why we use setdefault I think in place of setdefault first we should
convert that dictionary in the list and now we can add new value then
again
convert it in dictionary
You probably could convert it to a list, append a tuple and then convert
the list back to a dictionary. But why would you want to do that when
setdefault is so much easier?
Also the conversions between list and dictionary would take a lot of
time and computer power for a big dictionary
For example I tried
L = [(n,n) for n in range(1000000)]
d = dict(L)
d2 = [(k,v) for k,v in d.items()]
d.setdefault(-5,-5)
- producing the dict from the list took about half a second
- producing the list from the dict took over 3 seconds and
used over 50% of my CPU...
- using setdefault() was effectively instantaneous.
HTH,
--
Alan Gauld
Author of the Learn to Program web site
http://www.alan-g.me.uk/
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