Dynamically accessing variables in python

Question

There are 9 texts called text1, text2, ... text9. A function is defined as follow.

def lexical_diversity(text):
    return len(set(text))/len(text)

I want to call the function for all 9 texts with following code. But the outpu is wrong.

for i in range(1,10):
    a='text'+str(i)
    print(lexical_diversity(a))

My output is

0.8
0.8
...
0.8

If applying the function to text1, I get following result.

>>>lexical_diversity(text1)
   Out[37]:0.07406285585022564

So which part goes wrong?

'text'+str(i)gives "text1", "text2", ... the actual strings. So you get the lexical diversity of "text1", "text2", ... If you have multiple texts you want to access, you probably want to store them in an array, not in separated variables otherwise you cannot loop on them. — spectras
– spectras, Commented Aug 24, 2017 at 11:45
@LeiHao> well, I didn't add anything because cᴏʟᴅsᴘᴇᴇᴅ's answer below is the right way to do this. I would suggest you look for python list tutorial on your search engine of choice, you'll get a better understanding of how to handle lists of things :) — spectras
– spectras, Commented Aug 24, 2017 at 12:09

cs95 · Accepted Answer · 2017-08-24 11:51:42Z

4

You should understand that a = 'text' + str(i) does not magically bestow upon a the value of whatever is contained inside the variable text1. Instead, a is assigned to the string "text1". The two are not the same.

Given the names, you should probably consider storing your texts in a list:

texts = [text1, text2, text3, ...]

And now,

for a in texts:
    print(lexical_diversity(a))

edited Aug 24, 2017 at 11:51

answered Aug 24, 2017 at 11:47

cs95

406k106 gold badges744 silver badges797 bronze badges

Sign up to request clarification or add additional context in comments.

7 Comments

spectras Over a year ago

Given the names I would advocate an array. texts[i] sounds better than texts["text"+str(i)].

spectras Over a year ago

What I mean is given his variable names, I believe there is no semantic content in his text1, text2, .... He merely have texts, and added a number to his variables names.

Lei Hao Over a year ago

I see my errors. Is there a way to create this list quickly, instead of typing text1, text2,...? A for-loop or something?

cs95 Over a year ago

@LeiHao Yes. There's a quick and dirty solution. It involves manipulating globals. Do this: texts = [globals()['text' + str(i)] for i in range(1, 10)] You must wonder... why not use globals directly? Well, it's major code smell.

cs95 Over a year ago

@akp That just puts strings in there, not the actual variable content.

|

ricristian · Accepted Answer · 2017-08-24 12:02:13Z

0

Python3

def lexical_diversity(text):
    return len(set(text))/len(text)
lista = []
for i in range(1,10):
    lista.append("text%d" % i) 
for resVal in lista:
    print(resVal) 
    print(lexical_diversity(resVal))

answered Aug 24, 2017 at 12:02

ricristian

5344 silver badges19 bronze badges

Collectives™ on Stack Overflow

Dynamically accessing variables in python

2 Answers 2

7 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

7 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related