Question: Suppose I have a list like this:

```
['v_1', 'v_2', 'v_8', 'v_5']

```

How can I get 8 from this list?

Answer: 
You can convert the strings to numbers easily enough, and just take the maximum. Assuming everything in your list is of the form `"v_#"` where `#` is an integer:

```
m = max(int(x[2:]) for x in my_list)

```
The solution using `max()` and `str.index()` functions (considering `_` as separator):

```
l = ['v_1', 'v_2', 'v_8', 'v_5']
m = max(v[v.index('_')+1:] for v in l)

print(m)   # 8

```