Thanks for the help.
Actually this is part of a much larger project, but I have unfortunately
pigeon-holed myself into needing to do these things without a whole lot of
flexibility.
To give a specific example I have the following dictionary where I need to
remove values that are duplicated with other values and remove values that are
duplicates of the keys, but still retain it as a dictionary. Each value is
itself a class with many attributes that I need to call later on in the
program, but I cannot have duplicates because it would mess up some estimation
part of my model.
d =
{36: [35, 37, 26, 46], 75: [74, 76, 65, 85], 21: [20, 22, 11, 31], 22: [21, 23,
12, 32], 26: [25, 27, 16, 36], 30: [20, 31, 40]}
So I want a new dictionary that would get rid of the duplicate values of 21,
22, 36 and 20 and give me back a dictionary that looked like this:
new_d=
{36: [35, 37, 26, 46], 75: [74, 76, 65, 85], 21: [20, 11, 31], 22: [23, 12,
32], 26: [25, 27, 16], 30: [40]}
I understand that a dictionary may not be the best approach, but like I said I
have sort of pigeon-holed myself by the way that I am simulating my data and
the estimation model that I am using. Any suggestions or comments about the
above problem would be greatly appreciated.
Thanks again,
Krishna
>>> Dave Angel <[email protected]> 08/11/09 7:38 AM >>>
Krishna Pacifici wrote:
> Hi,
> kind of a newbie here, but I have two questions that are probably pretty
> simple.
>
> 1. I need to get rid of duplicate values that are associated with different
> keys in a dictionary. For example I have the following code.
> s={}
> s[0]=[10,2,3]
> s[10]=[22,23,24]
> s[20]=[45,5]
> s[30]=[2,4]
> s[40]=[6,7,8]
>
> Now I want to be able to loop through the primary keys and get rid of
> duplicates (both in keys and values) so that I would have either a new
> dictionary or the same dictionary but with the following values:
>
> s[0]=[3]
> s[10]=[22,23,24]
> s[20]=[45,5]
> s[30]=[2,4]
> s[40]=[6,7,8]
>
> It doesn't matter which value gets removed as long as there is only one
> remaining, so in this example it doesn't matter that 2 got removed from s[0]
> or from s[30] as long as there is only one 2 in the dictionary.
>
> 2. I need to be able to loop over the values in the dictionary when there
> are multiple values assigned to each key like above and assign new values to
> those values. Taking the above example I would want to assign a new value so
> that when you called s[0] it would equal [3,4] say if 4 was the new value. I
> think this should be as simple as adding a value, but I kept on having
> difficulty.
>
> Any suggestions would be greatly appreciated.
>
> Thank you very much,
> Krishna
>
>
>
Sounds like homework. If it was for an unconstrained project, I'd
design a different data structure, one that directly enforced the data
constraints. So far, I can't imagine a useful reason for this
particular set of constraints.
Let's break the problems down.
1a) Do you know how to write a loop that visits all the keys of a
dictionary?
1b) Do you know how to safely check if a particular key exists?
e.g. if key in s:
1c) Do you know how to collect a set of values, so that when a
duplicate is found, it can be recognized as such?
1d) Do you know how to remove an item from a list?
2a) Like 1a)
2b) Do you know how to append a value to the end of a list? Is s[key] a
list?
DaveA
--
http://mail.python.org/mailman/listinfo/python-list
