In Pandas, how to filter a Series based on the type of the values?

Question

Given a Series like

import pandas as pd

s = pd.Series([\'foo\', \'bar\', 42])

I would like to obtain a \'sub-series\' p

Answer 1

Use apply or list comprehension:

s[s.apply(lambda x: isinstance(x, str))]

Same as, thanks Jon Clements♦:

s[s.apply(isinstance, args=(str,))]

---

s[[isinstance(x, str) for x in s]]

All return:

0    foo
1    bar
dtype: object

EDIT:

This is not recommended, thanks cᴏʟᴅsᴘᴇᴇᴅ:

s[s.apply(type) == str]

Answer 2

I'd use pd.to_numeric as pointed above.

Alternatively, you can use str.isalpha

In [109]: s[s.str.isalpha().notnull()]
Out[109]:
0    foo
1    bar
dtype: object

Answer 3

A little trick with pd.to_numeric:

s[pd.to_numeric(s, errors='coerce').isnull()]

0    foo
1    bar
dtype: object

If an item is numeric, it is successfully coerced (not NaN) and so is dropped from the final result.