Pandas: delete consecutive duplicates but keep the first and last value

Question

So I have a set of values in a column that looks like this:

1 0 2 1 1 0 0 0 0 0 1 2 0 0 0 0 4 

I'm trying to delete the repeating zeros but keep the first and last ones. End result should look like this:

1 0 2 1 1 0 0 1 2 0 0 4

Drop duplicates won't work because it deletes all the zeros, not independent consecutive zeros.

df = df.loc[df.people.shift() != df.people]

this works well but does not save the last number of that consecutive one

Answer 1

Using fillna with limit

s[s.replace(0,np.nan).ffill(limit=1).bfill(limit=1).notnull()]
Out[387]: 
0     1
1     0
2     2
3     1
4     1
5     0
9     0
10    1
11    2
12    0
15    0
16    4
dtype: int64