Create variable names based on the elements of an array

Question

I'm relatively new to coding in python so go easy on me.

I want to create integer variables with the names of these variables based off elements of a string array and set them all to zero to start with (in order to save me manually coding 20 variables out). The string array is shown below.

filterKeywords = ['IBM', 'Microsoft', 'Facebook', 'Yahoo', 'Apple',
  'Google', 'Amazon', 'EBay', 'Diageo',
  'General Motors', 'General Electric', 'Telefonica', 'Rolls Royce',  
  'Walmart', 'HSBC', 'BP',
  'Investec', 'WWE', 'Time Warner', 'Santander Group']

I don't want the variable names to be exactly the name of the element in the array, however, I want the variable names to contain the elements from the array, for example: for the string element 'apple' I want my variable name to be 'applePositive'. I have tried to implement this and here it is below (I'm not sure if it is the correct format or not).

for word in filterKeywords:
    [word + "Positive"] = 0

I'm getting a "cannot assign to operator" error with this and I've tried also to cast it to an int but it doesn't work either.

Any help would be much appreciated!

Seconded. Creating variable names like that is not a good idea, nor is it possible with spaces in the strings. A dictionary would be more suitable. — Jake Griffin, Apr 06 '15 at 16:52

ComputerFellow · Accepted Answer · 2015-04-06T17:07:51.480

4

You're looking for a dict.

vars = {}
for word in filterKeywords:
    vars[word + "Positive"] = 0

Then use it however you want, for example, say, print vars["applePositive"].

You can access all your "names" with vars.keys()

You can do further computations on all the items too

for word, value in vars.iteritems():
    # do something
    print word, value

or

for i in vars:
    print i, vars[i]

And if at some point, you get suspicious if "applePositive" is in your dict and has a value, you can do 'applePositive' in vars, which will return either True or False.

And then if you decide to add 1 to the values of only Facebook and Apple, you can do that too

for i in ['applePositive', 'facebookPositive']:
    if i in vars:
        vars[i] += 1

edited Apr 06 '15 at 17:07

answered Apr 06 '15 at 16:46

ComputerFellow

11,710
12
50
61

Thanks for the quick response! As I said I'm relatively new to this so ill implement that into my code now – philmckendry Apr 06 '15 at 16:56
`applePositive in vars` is enough ... no need to extract the keys. – Julien Spronck Apr 06 '15 at 16:58
also ... when looping over the items, you might want to use the iterator version => `for word, value in var.iteritems():` – Julien Spronck Apr 06 '15 at 17:00
@JulienSpronck agreed again! – ComputerFellow Apr 06 '15 at 17:02

score 1 · Answer 2 · answered Apr 06 '15 at 16:49

You can use a dic comprehension to put each value to a dictionary

filterKeywords = ['IBM', 'Microsoft', 'Facebook', 'Yahoo', 'Apple']
d = {k + "positive":0 for k in filterKeywords}

Which outputs:

{'IBMpositive': 0, 'Yahoopositive': 0, 'Microsoftpositive': 0, 'Facebookpositive': 0, 'Applepositive': 0}

Create variable names based on the elements of an array

2 Answers2