python programming help

[Mark Lawrence]

On 08/12/2013 19:06, rafaellasav at gmail.com wrote:
> i get it, thanks a lot i wrote a different one and it works
>
> def people(age):
>      people=[name for name in dic if dic[name]==age]
>      print(people)
>
> people(20)
>
> i have one last question
>
> it asks me to test my program function by running these lines:
> print ’Dan’ in people(18) and ’Cathy’ in people(18)
> print ’Ed’ in people(19) and ’Helen’ in people(19) and\
> ’Irene’ in people(19) and ’Jack’ in people(19) and ’Larry’in
> people(19)
> print ’Alice’ in people(20) and ’Frank’ in people(20) and ’Gary’ in
> people(20)
> print people(21) == [’Bob’]
> print people(22) == [’Kelly’]
> print people(23) == []
>
> but when i wrote these lines it returns me an error
> Traceback (most recent call last):
>    File "/Users/rafaellasavva/Desktop/people.py", line 19, in <module>
>      print 'Dan' in people(18) and 'Cathy' in people(18)
> TypeError: argument of type 'NoneType' is not utterable
>
> do you know what it might be wrong?
>

You've typed up the error message instead of using cut and paste, which 
is why it says "utterable" instead of "iterable"? :)  Seriously, it's 
already been pointed out that your people function needs a return 
statement.  Without it, the default returned is always None.

Would you also please read and action this
https://wiki.python.org/moin/GoogleGroupsPython as it prevents us seeing 
huge numbers of unwanted newlines which some find extremely irritating.

-- 
My fellow Pythonistas, ask not what our language can do for you, ask 
what you can do for our language.

Mark Lawrence