[Tutor] replacing a long list of if,elif

[John]

On Friday 23 October 2009 08:05:29 am John wrote:
> I'm using python 2.5
>
> I have a long list of if, elif, else.  I always thought it was very NOT
> pythonic.  It's easy to read but not pretty.
>
> for fldType in fieldList:
>   if "int" in fldType:
>       fld = "I"
>   elif "char" in fldType :
>       fld = "C"
>   elif "bool" in fldType :
>      fld = "B" .....
>   else:
>      fld = '?'
>
>
> I have considered:
>
>   mydict = {'int': 'I', 'char':'C', 'bool':'B'....}
>   for fldType in fieldList:
>     try:
>         fld = mydict[fldType]
>     except:
>         fld = '?'
>
> I also considered some sort of  lambda function as
>
> x = lambda fld: mydict[fldType]
>
> But could not determine how to account for the key exception. So I tried
>
> x = lambda fldType: mydict[fldType]
> if fldType in mydict:
>    x(fldType)
> else:
>     fld = '?'
>
>
> Any suggestions would be helpful  and would help me learn.
>
> Johnf

>John,

>Using a Dictionary is the best method to use here and you can use dict.get
>in order to bypass the KeyError

>EX:

>myDict.get(fldType, None)

>this will output the value from myDict if the key exists, if not it will
>
>return None 

Thanks this looks perfect - did not know dict.get()

Johnf


Vince