如何遍歷數組數組中的鍵？

Question

我有一個數組，說：

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

我想根據按鍵檢查輸入，例如：

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

keys()不起作用-我應該怎么辦？

Answer 1

列表沒有鍵...您只想要每個子列表的第一個元素

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

要么

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

要么

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

要么

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

Answer 2

keys不是list的方法。 你一定在想一本dict 。 做就是了：

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