Can I use python slicing to access one "column" of a nested tuple?

Question

I have a nested tuple that is basically a 2D table (returned from a MySQL query). Can I use slicing to get a list or tuple of one "column" of the table? For example: ``` t = ((1,2,3),(3,4,5),(1,4,5),(9,8,7)) x = 6 ``` How do I efficiently check whether `x` appears in the 3rd position of any of the tuples? All the examples of slicing I can find only operate within a single tuple. I don't want to slice a "row" out of t. I want to slice it the other way -- vertically.

Accepted Answer

Your best bet here is to use a generator expression with the `any()` function:

```
if any(row[2] == x for row in t):
    # x appears in the third row of at least one tuple, do something
```

As far as using slicing to just get a column, here are a couple of options:

Using `zip()`:

```
>>> zip(*t)[2]
(3, 5, 5, 7)
```

Using a list comprehension:

```
>>> [row[2] for row in t]
[3, 5, 5, 7]
```

Can I use python slicing to access one "column" of a nested tuple?

Solution

Problem