a value is trying to be set on a copy of a slice from a dataframe error in python code example

Example: A value is trying to be set on a copy of a slice from a DataFrame.

# Error:
# SettingWithCopyWarning: A value is trying to be set on a copy of a
# slice from a DataFrame

# As explained in the Source, this warning is usually safe to ignore. You
# can disable it by running the following:

import pandas as pd
pd.options.mode.chained_assignment = None  # default='warn'