How do I transform a matrix into a vector?

I have this matrix that contains x number of products and feedback rankings of 5 different categories.
This matrix is represented in a Pandas DataFrame like this:

How do I transform a matrix such as this to show the overall rank of each product?
E.g. like this where 0 is the worst and 9 is the best:

>Solution :

Something like this?

df['Bad ratings'] *= -2
df['Slightly bad ratings'] *= -1
df['Good ratings'] *= 2

df.set_index('index').sum(1).rank().sort_values()

Output:

index
product1     1.0
product3     2.0
product4     3.0
product2     4.0
product5     5.0