[Tutor] Using a string to get at a Variable
hcohen2 at comcast.net
Sun Jan 18 21:29:03 EST 2004
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
>Tutor maillist - Tutor at python.org
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.
names_tuple = (var_1, var_2, ..., var_n)
len_tuple = len(names_tuple)
for j in range(len_tuple):
len_obj = len(var_j)
for i in range(len_obj):
value_of_obj(i) = var_i[i]
print 'Show me the value of %s' %
# Or do whatever you have in mind, e.g.
storing in a dictionary, etc.
except ValueError, TypeError, diag: #
regarding the errors I am guessing
except TypeError, RangeError, 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.
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