[Baypiggies] How to create a dict of counts using functional programming

[David Berthelot]

There's already a function written for that though in the standard library:
https://docs.python.org/2/library/collections.html#collections.Counter

On Mon, Sep 28, 2015 at 4:01 AM, Braun Brelin <bbrelin at gmail.com> wrote:

> Hello all,
>
> I am trying to do the following:
> I have a list that looks like this:
> ['1','2','7','8','8']
>
> I want to create a dictionary that looks like this:
> {1:1, 2:1,7:1,8:2}
> i.e. the value is the count of the number of times the key appears in
> the list.  The catch is that I'm trying to do this in a functional
> programming way, rather than iteratively.
>
> I'm trying to use something like map, or reduce or even dict, but I can't
> figure out how to tell
> python to increment the value.  In other words how do I even specify what
> the value is, as it
> seems to be a bit of a chicken and egg scenario.
>
> I can, for example create a dictionary that sets the values to a constant,
> such as zero using FP,
> but how do I tell it to increment the value for a dictionary that doesn't
> yet exist as I'm in the process of
> building it?
>
> Thanks,
>
> Braun Brelin
>
>
>
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