How to iterate over keys in array of arrays?

Question

I have an array, say:

products = [['product_1','description 1'],['product_2','description 2']]

And I want to check input against the keys, e.g.,:

product = raw_input('Enter product:  ')
if product not in products.keys():
    log.fatal('Invalid product: {}'.format(product))
    exit(1)

keys() doesn't work -- what should I be doing?

Joran Beasley · Accepted Answer · 2016-06-23 20:00:56Z

2

lists dont have keys ... you just want the first element of each sublist

dict(products).keys() #ONLY if there is exactly 2 items per sublist

or

zip(*products)[0] #any number of items per sublist is ok

or

[k for k,val in products] # only if you have EXACTLY 2 items per sublist

or

[item[0] for item in products]  # any number of items in each sublist

answered Jun 23, 2016 at 20:00

Joran Beasley

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Comments

Guillaume Thomas · Accepted Answer · 2016-06-23 20:02:07Z

2

keys is not a method of a list. You must be thinking of a dict. Just do:

products = {k: v for k, v in [['product_1','description 1'],['product_2','description 2']]}

answered Jun 23, 2016 at 20:02

Guillaume Thomas

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or just call dict on your list directly ... good answer all the same