[Tutor] Using a string to get at a Variable

[hcohen2]

Isr Gish wrote:

>-----Original Message-----
>   >From: "hcohen2"<hcohen2 at comcast.net>
>   >Sent: 1/18/04 9:29:03 PM
>   >To: "Isr Gish"<isrgish at fusemail.com>
>   >Cc: "Tutor"<tutor at python.org>
>   >Subject: Re: [Tutor] Using a string to get at a Variable
>   >
>   >Isr Gish wrote:
>   >
>   >>I'm trying to get the data from a variable using a string.
>   >>For example I have three variables named apples, grapes, pears. Then I have a list with these 3 names as strings.
>   >>Now I would like to do a loop on the list and getsthe data from each name.
>   >>
>   >>Any help would be greatly appreciated.
>   >>
>   >>Thanks in Advance
>   >>
>   >>---------------
>   >>Isr Gish
>   >>
>   >>
>   >>_______________________________________________
>   >>Tutor maillist  -  Tutor at python.org
>   >>http://mail.python.org/mailman/listinfo/tutor
>   >>
>   >>  
>   >>
>   >Ist,
>   >
>   >You are not very explicit on either on what you on working with nor the 
>   >sort of object that contains the data you are seeking to extract, hence, 
>   >I will just outline an example of my own design.
>   >
>   >Let's say you get you set of variables as a tuple: (var_1, var_2, ..., 
>   >var_n) - I am going to assume these variables are names of lists.  So I 
>   >see no real need to convert them to strings.  If that is indeed 
>   >necessary, skip the entire discussion.
>   >
>   >#Intermediate result
>   >names_tuple = (var_1, var_2, ..., var_n)
>   >len_tuple = len(names_tuple)
>   >for j in range(len_tuple):
>   >        try:
>   >                len_obj = len(var_j)
>   >                for i in range(len_obj):
>   >                        value_of_obj(i) = var_i[i]
>   >                         try:
>   >                                print 'Show me the value of %s' %   
>   >names_tuple[j],
>   >                                print var_i[i]
>   >                                # Or do whatever you have in mind, e.g. 
>   >storing in a dictionary, etc.
>   >                         except ValueError, TypeError, diag:      # 
>   >regarding the errors I am guessing
>   >                               print str(diag)
>   >       except TypeError, RangeError, diag:
>   >                 print str(diag)
>   >
>   >I am not sure how useful you will find this nor how close it is to 
>   >solving the problem you are attacking - just recognize I am new at 
>   >python.  Moreover, I may miss the clues to the type of problem, since my 
>   >specialty is databases and much of the discussion here leaves me a bit 
>   >puzzled as to where they are being applied.
>   >
>   >In any case, I hope it helps a bit.
>   >Herschel
>   >
>
>I don't understand the code you wrote, and what exactly its supposed to do.
>But this is what I'm looking for.
>
>apples = 10
>grapes = 5
>pears = 8
>fruits = ['apples', 'grapes', 'pears']
>Now Iswant to be able to do something like this.
>for fruit in fruits:
>	print 'You heve %d' % (fruit), fruit
>
>And the output should look like this:
>You have 10 apples
>You have 5 grapes
>You have 8 pears
>
>Thanks for the reply and if anyone can help it would be appreciated.
>
>Isr Gish
>
>
>_______________________________________________
>Tutor maillist  -  Tutor at python.org
>http://mail.python.org/mailman/listinfo/tutor
>
>  
>
Isr,

Sorry, I tend to look for complex problems and obviously I misread your 
question.  My response is perhaps a reflection of my thoughts: getting a 
intermediate set of objects that are themselves objects that hold data.

Again sorry for the confusion - got too excited wondering what you could 
be after?

Herschel