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, eg,:

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?

Answer 1

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

Answer 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']]}