Pandas: change data type of Series to String

You can convert all elements of id to str using apply

df.id.apply(str)

0        123
1        512
2      zhub1
3    12354.3
4        129
5        753
6        295
7        610

Edit by OP:

I think the issue was related to the Python version (2.7.), this worked:

df['id'].astype(basestring)
0        123
1        512
2      zhub1
3    12354.3
4        129
5        753
6        295
7        610
Name: id, dtype: object