Python Pandas: Replacement method for convert_objects()

The DataFrames.convert_objects() in Pandas is a very useful function to try to infer better data types for you imported data.

For example if you have just imported hockey player stats and the data looks like:

df.dtypes

Out[1]: 

PLAYER    object

TEAM      object

GP        object

G         object

A         object

PTS       object

+/-       object

dtype: object

Using convert_objects:

df.convert_objects(convert_numeric=True).dtypes

 __main__:1: FutureWarning: convert_objects is deprecated.  Use the data-type specific converters pd.to_datetime, pd.to_timedelta and pd.to_numeric.

Out[2]: 

PLAYER     object

TEAM       object

GP          int64

G           int64

A           int64

PTS         int64

+/-         int64

dtype: object

The return information indicates that it is deprecated, but isn't clear on a suitable replacement, because while convert_objects() tried to infer all columns in the data frame, pandas.to_numeric() is applied to a specific column. The solution is to combine it with the DataFrame.apply():

df.apply(pd.to_numeric, errors='ignore').dtypes
Out[3]: 
PLAYER     object
TEAM       object
GP          int64
G           int64
A           int64
PTS         int64
+/-         int64
dtype: object