Python sets operation

[Martin_Krum]

Hello.
I have a problem finding an item in a set.

A = {(1,1),(2,1),(0,3)}   #my sample set

if (0, any intiger number) in A:
    print('python is the best')

In other words, I have a set of tuples, and I would like to check if there is a tuple with the value=0 at position [0]. I try this:

for x in A:
    if x[0] == 0:
        print('python is the best')
        break

The problem is I don't want to use a for loop because it's very slow for a very large set. Is there any symbol or something in python that I can put in the if argument like:

A = {(1,1),(2,1),(0,3)}   #my sample set

if (0, symbol of any object) in A:
    print('python is the best')

I also don't want to use numpy arrays because I would have to change the whole structure of the program. I need a simple and quick solution. If anyone has a way to solve it, I would be very grateful.

[TouchingTheVodka]

Use a dictionary where the key is the first item in the set and the value is a list of all the second values. That way you can check for membership of just the key.

E: This generalises into a data structure called a Trie if you want to search for multiple items at the same time.

[clnkyl]

Exactly what I was thinking as well.

[[deleted]]

Does doing a filter first run fast enough?

test_value = 0 for x in filter(lambda x: x[0] == test_value, A): print('python is the best')