import pandas as pd

>>> df
  country
0        US
1        UK
2   Germany
3     China
>>> countries_to_keep
['UK', 'China']
>>> df.country.isin(countries_to_keep)
0    False
1     True
2    False
3     True
Name: country, dtype: bool
>>> df[df.country.isin(countries_to_keep)]
  country
1        UK
3     China
>>> df[~df.country.isin(countries_to_keep)]
  country
0        US
2   Germany