changing dtype of second axis in pandas dataframe

Question

When i do the following :

df.axes

I get:

[Int64Index([1970, 1971, 1972, 1973, 1974, 1975, 1976, 1977, 1978, 1979, 1980,
             1981, 1982, 1983, 1984, 1985, 1986, 1987, 1988, 1989, 1990, 1991,
             1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002,
             2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013,
             2014, 2015, 2016, 2017, 2018, 2019, 2020],
            dtype='int64'),

 Index(['0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '10', '11', '12',
        '13', '14', '15', '16', '17', '18', '19', '20', '21', '22', '23', '24',
        '25', '26', '27', '28', '29', '30', '31', '32', '33', '34', '35', '36',
        '37', '38', '39', '40', '41', '42', '43', '44', '45', '46', '47', '48',
        '49', '50', '51', '52', '53', '54', '55', '56', '57', '58', '59', '60',
        '61', '62', '63', '64', '65', '66', '67', '68', '69', '70', '71', '72',
        '73', '74', '75', '76', '77', '78', '79', '80', '81', '82', '83', '84',
        '85', '86', '87', '88', '89'],
       dtype='object')]

I want to change the dtype of the second index. How do I do this?

Kind regards.

Answer 1

You cast it by hand and reassign the columns:

df.columns = [int(col) for col in df]