I am newbie who can explain this code to me?
380162267qq at gmail.com
380162267qq at gmail.com
Thu Sep 22 15:22:36 EDT 2016
在 2016年9月20日星期二 UTC-4下午3:11:27,Terry Reedy写道:
> On 9/20/2016 9:12 AM, Peter Otten wrote:
>
> >> 在 2016年9月20日星期二 UTC-4上午8:17:13,BartC写道:
> >>> On 20/09/2016 13:12, 380162267qq at gmail.com wrote:
> >>>>>>> d = {}
> >>>>>>> keys = range(256)
> >>>>>>> vals = map(chr, keys)
> >>>>>>> map(operator.setitem, [d]*len(keys), keys, vals)
> >>>>
> >>>> It is from python library. What does [d]*len(keys) mean?
> >>>> d is the name of dict but put d in [] really confused me.
>
> Where in which 'python library? I cannot findI the above in 2.7 or 3.6
> stdlib. The code should be replaced by
>
> > It should be noted that the code above is really bad Python.
> > Better alternatives are the simple loop
> >
> > d = {}
> > for i in range(256):
> > d[i] = chr(i)
> >
> > or the dict comprehension
> >
> > d = {i: chr(i) for i in range(256)}
>
> this.
>
> --
> Terry Jan Reedy
I read an old 3.2 library and didn't notice at that time.
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