argument matching question

[Learning Python]

I know this is dummy, just never saw an example of this.


I want to use the special argument matching.

A code like this:

def adder(**varargs ):
sum=varargs[varargs.keys()[0]]
for next in varargs.keys()[1:]:
sum=sum+varargs[next]
return sum

print adder( "first","second ",'third')


------------------------
It pop up error like this:

Traceback (most recent call last):
File "learn.py", line 7, in ?
print adder( "first","second ",'third')
TypeError: adder() takes exactly 0 arguments (3 given)


How to pass arguments to a functions that use dictionary collection?


Thanks

[Leif K-Brooks]

Re: argument matching question

Learning Python wrote:[color=blue]
> A code like this:
>
> def adder(**varargs ):
> sum=varargs[varargs.keys()[0]]
> for next in varargs.keys()[1:]:
> sum=sum+varargs[next]
> return sum
>
> print adder( "first","second ",'third')
>
> How to pass arguments to a functions that use dictionary collection?[/color]

Like adder(foo="bar" , bar="baz"), but I think you really want a function
like this:

def adder(*args):
sum = args[0]
for value in args[1:]:
sum += value
return sum

[Learning Python]

Re: argument matching question

thanks, got it.
I want to test the **name option for argument matching.

[Scott David Daniels]

Re: argument matching question

Leif K-Brooks wrote:[color=blue]
> Learning Python wrote:
>[color=green]
>>A code like this:
>>
>>def adder(**varargs ):
>> sum=varargs[varargs.keys()[0]]
>> for next in varargs.keys()[1:]:
>> sum=sum+varargs[next]
>> return sum[/color][/color]

For that function, call:
print adder(first=1, second=2, third=3)

A better function definition for python 2.4 would be:
def adder(**varargs ):
return sum(varargs.val ues())
And a better function definition without using sum would be:
def adder(**varargs ):
values = varargs.values( )
if values:
total = values[0]
for element in values[1:]:
total += element
return total
else:
return 0

--Scott David Daniels
Scott.Daniels@A cm.Org