Get first and last elements from list according to enumerate list Python

Question

I have column in Pandas full of lists. Each row looks like:

row_1 = [7, 8, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23]
row_2 = [7, 8, 9, 15, 16, 17, 18, 19]
...
row_n = [27, 28, 29, 30, 31, 32, 33, 34, 35]

And I need to get boundary values and insert them to the tuple, eg

full_list = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, ...,35]

and according to the list above find first and last values:

row_tuple_1 = [(7, 8), (14, 23)]
row_tuple_2 = [(7, 9), (15, 19)]
...
row_tuple_n = [(27, 35)]

Is there a way to do that?

Upd1:

Imagine that full_list is how row_1 should look's like. But it's not.

Another option to write row_1 is:

row_1 = [np.nan, np.nan, np.nan, np.nan, np.nan, np.nan, np.nan, 7, 8, np.nan, 
np.nan, np.nan, np.nan, np.nan, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, np.nan, ...]

So (start, end) tuple should be (7, 8) and (14, 23)

Answer 1

Finally know what you need, we need using groupby for each row

def func(x):
    s=pd.Series(x)
    return s.groupby(s.diff().ne(1).cumsum()).agg(['first','last']).values.tolist()
df.L.apply(func)
Out[145]: 
0    [[7, 8], [14, 23]]
1    [[7, 9], [15, 19]]
2            [[27, 35]]
Name: L, dtype: object