Answers for "how to convert object to category in python"

pandas convert multiple columns to categorical

#Two ways to do this
df[['parks', 'playgrounds', 'sports']].apply(lambda x: x.astype('category'))

cols = ['parks', 'playgrounds', 'sports', 'roading']:
public[cols] = public[cols].astype('category')

how to convert each string to a category or int in python dataframe

In [3]: df = pd.DataFrame({"A": ["a", "b", "c", "a"]})

In [4]: df["B"] = df["A"].astype('category')

In [5]: df
Out[5]: 
   A  B
0  a  a
1  b  b
2  c  c
3  a  a