Cycling through a group of variables with similar names

Question

Is there a way to cycle through a group of variables with similar names using a for loop in python?

An example (from the nltk library): I have a group of variables called text1, text2, text3, ..., text9, and I want to do certain operations to all of them without having to explicitly type their names each time, so I'm looking for a way to loop through them like this:

for x in range(1, 9):
    text + x.someFunction()

I know this is not allowed, but is there a way to do something like that?

You shouldn't be having those variables in the first place. For example, a list called `texts` would be a better solution, then iterating over that is trivial. — Tim Pietzcker, Apr 24 '14 at 10:12
These variables are in a library (the nltk library) so it isn't me who have named them. — Arash Saidi, Apr 24 '14 at 10:14
Assuming it's `nltk.book`, these variables hold example data meant to be used at an interactive prompt while following a tutorial. — user2357112, Apr 24 '14 at 10:21
yeah, it's nltk.book. I guess it's not meant to be used the way I am trying to use them, but I don't like following tutorials without doing my own experiments... — Arash Saidi, Apr 24 '14 at 10:26

score 3 · Accepted Answer · answered Apr 24 '14 at 10:13

You can use eval:

eval("text" + str(1))

For example, to load your values in a map:

data = dict()
for x in xrange(1, 9):
    key = "text" + str(x)
    data[key] = eval(key)

Or if your variables are objects of a class with a method someFunction:

for x in xrange(1, 9):
    cmd = "text" + str(x) + ".someFunction()"
    eval(cmd)

score 0 · Answer 2 · edited May 23 '17 at 11:57

0

You can use eval

for x in range(1, 9):
    eval('text%d' % x).someFunction()

Refer: What does Python's eval() do? ;

edited May 23 '17 at 11:57

Community

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answered Apr 24 '14 at 10:14

Buddhima Gamlath

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score 0 · Answer 3 · answered Apr 24 '14 at 10:19

0

Try this.

for v in (text1, text2, text3):
    v.someFunction()

answered Apr 24 '14 at 10:19

Kei Minagawa

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score 0 · Answer 4 · answered Apr 24 '14 at 10:20

Make a list:

texts = [text1, text2, text3, text4, text5, text6, text7, text8, text9]

Then you can iterate over it as you would any other list:

for text in texts:

I'm assuming the textn variables aren't expected to change. If you're using the example data from nltk.book, I believe that assumption should hold.

Cycling through a group of variables with similar names

4 Answers4