how to change a column from float to int in pandas code example

Example 1: convert float to integer pandas

>>> df['C'] = df['C'].apply(np.int64)
>>> print(df)
...    A  B  C         D
... 0  8  0  1  6.226750
... 1  1  9  9  8.522808
... 2  1  4  2  7.739108

Example 2: convert all columns to float pandas

You have four main options for converting types in pandas:

to_numeric() - provides functionality to safely convert non-numeric types (e.g. strings) to a suitable numeric type. (See also to_datetime() and to_timedelta().)

astype() - convert (almost) any type to (almost) any other type (even if it's not necessarily sensible to do so). Also allows you to convert to categorial types (very useful).

infer_objects() - a utility method to convert object columns holding Python objects to a pandas type if possible.

convert_dtypes() - convert DataFrame columns to the "best possible" dtype that supports pd.NA (pandas' object to indicate a missing value).

Read on for more detailed explanations and usage of each of these methods.