def month_name(self, locale=None):
if self.tz is not None and not timezones.is_utc(self.tz):<EOL><INDENT>values = self._local_timestamps()<EOL><DEDENT>else:<EOL><INDENT>values = self.asi8<EOL><DEDENT>result = fields.get_date_name_field(values, '<STR_LIT>',<EOL>locale=locale)<EOL>result = self._maybe_mask_results(result, fill_value=None)<EOL>return result<EOL>
Return the month names of the DateTimeIndex with specified locale.

.. versionadded:: 0.23.0

Parameters
----------
locale : str, optional
    Locale determining the language in which to return the month name.
    Default is English locale.

Returns
-------
Index
    Index of month names.

Examples
--------
>>> idx = pd.date_range(start='2018-01', freq='M', periods=3)
>>> idx
DatetimeIndex(['2018-01-31', '2018-02-28', '2018-03-31'],
              dtype='datetime64[ns]', freq='M')
>>> idx.month_name()
Index(['January', 'February', 'March'], dtype='object')