uts.

    Examples
    --------
    Parsing a single string to a Timedelta:

    >>> pd.to_timedelta('1 days 06:05:01.00003')
    Timedelta('1 days 06:05:01.000030')
    >>> pd.to_timedelta('15.5us')
    Timedelta('0 days 00:00:00.000015500')

    Parsing a list or array of strings:

    >>> pd.to_timedelta(['1 days 06:05:01.00003', '15.5us', 'nan'])
    TimedeltaIndex(['1 days 06:05:01.000030', '0 days 00:00:00.000015500', NaT],
                   dtype='timedelta64[ns]', freq=None)

    Converting numbers by specifying the `unit` keyword argument:

    >>> pd.to_timedelta(np.arange(5), unit='s')
    TimedeltaIndex(['0 days 00:00:00', '0 days 00:00:01', '0 days 00:00:02',
                    '0 days 00:00:03', '0 days 00:00:04'],
                   dtype='timedelta64[ns]', freq=None)
    >>> pd.to_timedelta(np.arange(5), unit='d')
    TimedeltaIndex(['0 days', '1 days', '2 days', '3 days', '4 days'],
                   dtype='timedelta64[ns]', freq=None)
    N)