def strftime(self, dt, fmt=None):
    'Refer to documentation for datetime.strftime.\n\n        *fmt* is a :func:`strftime` format string.\n\n        Warning: For years before 1900, depending upon the current\n        locale it is possible that the year displayed with %x might\n        be incorrect. For years before 100, %y and %Y will yield\n        zero-padded strings.\n        '
    if (fmt is None):
        fmt = self.fmt
    fmt = self.illegal_s.sub('\\1', fmt)
    fmt = fmt.replace('%s', 's')
    if (dt.year >= 1900):
        return cbook.unicode_safe(dt.strftime(fmt))
    return self.strftime_pre_1900(dt, fmt)
Refer to documentation for datetime.strftime.

*fmt* is a :func:`strftime` format string.

Warning: For years before 1900, depending upon the current
locale it is possible that the year displayed with %x might
be incorrect. For years before 100, %y and %Y will yield
zero-padded strings.
def strftime(self, dt, fmt=None):
    'Refer to documentation for datetime.strftime.\n\n        *fmt* is a :func:`strftime` format string.\n\n        Warning: For years before 1900, depending upon the current\n        locale it is possible that the year displayed with %x might\n        be incorrect. For years before 100, %y and %Y will yield\n        zero-padded strings.\n        '
    if (fmt is None):
        fmt = self.fmt
    fmt = self.illegal_s.sub('\\1', fmt)
    fmt = fmt.replace('%s', 's')
    if (dt.year >= 1900):
        return cbook.unicode_safe(dt.strftime(fmt))
    return self.strftime_pre_1900(dt, fmt)