[Tutor] Update values stored as a list in a dictionary with values from another dictionary

[GTXY20]

I have the transFn function as follows:

def transFn(translatefile):
    transfile = open(translatefile, 'r')
    records = transfile.read()
    transfile.close()
    lines = records.split()
    transDict = {}
    for line in lines:
        key, value = line.split(',')
        transDict[key] = value

    for key, value in data.items():
      data[key] = [ x for x in (transDict.get(i, i) for i in value) if x is
not None]

my original data is:

data = {'1': ['a', 'b', 'c'], '3': ['a', 'b', 'c'], '2': ['a', 'b', 'c'],
'4': ['a', 'c']}

my transDict is:

transDict = {'a': '1', 'b': '2'}

However when I run transFn my data is:

data = {'1': ['1', '2', 'c'], '3': ['1', '2', 'c'], '2': ['1', '2', 'c'],
'4': ['1', 'c']}

I was expecting:

{'1': ['1', '2'], '3': ['1', '2'], '2': ['1', '2'], '4': ['1']}

I will see if I can work with a remove command??

M.

On 10/2/07, Kent Johnson <kent37 at tds.net> wrote:
>
> GTXY20 wrote:
> > Here's an interesting question:
> >
> > Can I use the transFn function to remove items in the value list.
> >
> > Can this be done by simple assigning the current value a value of null
> > in the translate file?
>
> No, that will make the translated value be None (I guess that is what
> you mean by null). You could then filter for these, for example
>
>      for key, value in Data.items():
>         Data[key] = [ transDict.get(i, i) for i in value if
> transDict.get(i, i) is not None]
>
> If you want to avoid double-fetching from transDict (if Data is huge
> this might matter) then you could write out the loop or possibly use
> something like
>    Data[key] = [ x for x in (transDict.get(i, i) for i in value) if x is
> not None]
>
> which makes an intermediate generator and filters that.
>
> Kent
>
> >
> > M.
> >
> >
> >
> > On 10/2/07, GTXY20 <gtxy20 at gmail.com> wrote:
> >> I adjusted so that I get the following so if I do not need to translate
> a
> >> dictionary I do not call the function transFn:
> >>
> >> def transFn(translatefile):
> >>     transfile = open(translatefile, 'r')
> >>     records = transfile.read()
> >>     transfile.close()
> >>     lines = records.split()
> >>     transDict = {}
> >>     for line in lines:
> >>         key, value = line.split(',')
> >>         transDict[key] = value
> >>
> >>     for key, value in Data.items():
> >>       Data[key] = [ transDict.get(i, i) for i in value ]
>
>
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