Re: python programming help

References	<264c1144-5d04-4ad0-aa32-f4e6770d210c@googlegroups.com> <mailman.3733.1386527267.18130.python-list@python.org> <2243d31b-f2cb-484a-b6a3-f9f265aa8fd6@googlegroups.com>
From	Benjamin Kaplan <benjamin.kaplan@case.edu>
Date	2013-12-08 10:52 -0800
Subject	Re: python programming help
Newsgroups	comp.lang.python
Message-ID	<mailman.3737.1386529135.18130.python-list@python.org> (permalink)

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On Sun, Dec 8, 2013 at 10:32 AM, <rafaellasav@gmail.com> wrote:
>
> On Sunday, December 8, 2013 6:27:34 PM UTC, bob gailer wrote:
> > On 12/8/2013 12:59 PM, rafaellasav@gmail.com wrote:
> >
> > > i have a dictionary with names and ages for each name. I want to write a function that takes in an age and returns the names of all the people who are that age.
> >
> > > please help
> >
> > Welcome to the python list. Thanks for posting a question.
> >
> >
> >
> > If you were hoping for one of us to write the program for you ... well
> >
> > that's not what we do on this list.
> >
> >
> >
> > Please post the code you have so far and tell us exactly where you need
> >
> > help.
> >
> >
> >
> > Also tell us what version of Python, what OS, and what you use to write
> >
> > and run Python programs.
>
> name = ['Alice', 'Bob', 'Cathy', 'Dan', 'Ed', 'Frank', 'Gary', 'Helen', 'Irene', 'Jack', 'Kelly', 'Larry']
> age = [20, 21, 18, 18, 19, 20, 20, 19, 19, 19, 22, 19]
> dic={}
> def combine_lists(name,age):
>     for i in range(len(name)):
>         dic[name[i]]= age[i]
> combine_lists(name,age)
> print dic
>
> def people(age):
>     people=lambda age: [name for name in dic if dic[name]==age]
>
> people(20)
>
>
>
>
> this is the code i have so far(with the help of the first post ;p). i understand how a function and a dictionary works and what I'm asked to find. but i don't get the lambda age part. and this code doesn't give me any result
>
>

To return a value from a function, you need to use the "return"
statement with the value you want to pass back out. You're not doing
that here. Also, you're using a lot of shorthand stuff that you should
probably avoid until you're more comfortable with the language

* Lambda is shorthand for a function. foo = lambda bar : bar + 2 is
the same thing as the function
def foo(bar) :
    return bar + 2

* a list comprehension is short-hand for a loop. spam = [foo for foo
in bar if baz(foo)]  is the same thing as
spam = []
for foo in bar :
    if baz(foo) :
        spam.append(foo)

You don't need a lambda here- just call the code that you need to call directly.

Thread

python programming help rafaellasav@gmail.com - 2013-12-08 09:59 -0800
  Re: python programming help YBM <ybmess@nooos.fr.invalid> - 2013-12-08 19:07 +0100
    Re: python programming help rafaellasav@gmail.com - 2013-12-08 10:14 -0800
      Re: python programming help YBM <ybmess@nooos.fr.invalid> - 2013-12-08 19:18 +0100
      Re: python programming help Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-12-08 18:25 +0000
      Re: python programming help Christopher Welborn <cjwelborn@live.com> - 2013-12-09 17:34 -0600
  Re: python programming help Roy Smith <roy@panix.com> - 2013-12-08 13:23 -0500
  Re: python programming help Gary Herron <gary.herron@islandtraining.com> - 2013-12-08 10:20 -0800
  Re: python programming help bob gailer <bgailer@gmail.com> - 2013-12-08 13:27 -0500
    Re: python programming help rafaellasav@gmail.com - 2013-12-08 10:32 -0800
      Re: python programming help rafaellasav@gmail.com - 2013-12-08 10:42 -0800
      Re: python programming help Benjamin Kaplan <benjamin.kaplan@case.edu> - 2013-12-08 10:52 -0800
        Re: python programming help rafaellasav@gmail.com - 2013-12-08 11:06 -0800
          Re: python programming help Chris Angelico <rosuav@gmail.com> - 2013-12-09 06:17 +1100
            Re: python programming help rurpy@yahoo.com - 2013-12-08 16:08 -0800
              Re: python programming help Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-12-09 00:27 +0000
                Re: python programming help rurpy@yahoo.com - 2013-12-08 21:07 -0800
                Re: python programming help rusi <rustompmody@gmail.com> - 2013-12-08 21:20 -0800
                Re: python programming help rurpy@yahoo.com - 2013-12-09 21:15 -0800
                Re: python programming help Chris Angelico <rosuav@gmail.com> - 2013-12-09 18:57 +1100
                Re: python programming help rurpy@yahoo.com - 2013-12-09 21:07 -0800
                Re: python programming help Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-12-09 09:34 +0000
                Meta Fight About Posting (was: python programming help) Travis Griggs <travisgriggs@gmail.com> - 2013-12-09 07:44 -0800
                Re: Meta Fight About Posting (was: python programming help) rusi <rustompmody@gmail.com> - 2013-12-09 08:25 -0800
                Re: Meta Fight About Posting (was: python programming help) rusi <rustompmody@gmail.com> - 2013-12-09 08:47 -0800
                Re: Meta Fight About Posting (was: python programming help) Roy Smith <roy@panix.com> - 2013-12-09 13:48 -0500
                Re: Meta Fight About Posting (was: python programming help) Roy Smith <roy@panix.com> - 2013-12-09 13:45 -0500
              Re: python programming help Chris Angelico <rosuav@gmail.com> - 2013-12-09 14:05 +1100
                Re: python programming help rurpy@yahoo.com - 2013-12-08 21:10 -0800
                Re: python programming help Joel Goldstick <joel.goldstick@gmail.com> - 2013-12-09 00:22 -0500
                Re: python programming help Chris Angelico <rosuav@gmail.com> - 2013-12-09 19:15 +1100
                Re: python programming help rurpy@yahoo.com - 2013-12-09 21:10 -0800
                Re: python programming help Chris Angelico <rosuav@gmail.com> - 2013-12-10 16:29 +1100
          Re: python programming help Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-12-08 19:21 +0000
          Re: python programming help Terry Reedy <tjreedy@udel.edu> - 2013-12-08 16:17 -0500
          Re: python programming help YBM <ybmess@nooos.fr.invalid> - 2013-12-09 03:02 +0100
      Re: python programming help John Ladasky <john_ladasky@sbcglobal.net> - 2013-12-08 11:21 -0800
      Re: python programming help Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2013-12-09 13:00 +1300
        Re: python programming help YBM <ybmess@nooos.fr.invalid> - 2013-12-09 02:51 +0100
      Re: python programming help YBM <ybmess@nooos.fr.invalid> - 2013-12-09 03:31 +0100

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