i = 4
'{:6d} {:6d} {:6d} {:6d}'.format(i, i ** 2, i ** 3, i ** 4)
Out[11]: ' 4 16 64 256'
'{0:6d} {0:6d} {0:6d} {0:6d}'.format(i, i ** 2, i ** 3, i ** 4)
Out[12]: ' 4 4 4 4'
'{0:6d} {1:6d} {2:6d} {3:6d}'.format(i, i ** 2, i ** 3, i ** 4)
Out[13]: ' 4 16 64 256'
'{0:06d} {1:06d} {2:06d} {3:06d}'.format(i, i ** 2, i ** 3, i ** 4)
Out[14]: '000004 000016 000064 000256'
'{0:06} {1:06} {2:06} {3:06}'.format(i, i ** 2, i ** 3, i ** 4)
Out[15]: '000004 000016 000064 000256'