Maybe this shouldn’t be an answer, but it could be helpful for some: the built-in format
function does convert numbers to string in a few bases:
>>> format(255, 'b') # base 2
'11111111'
>>> format(255, 'd') # base 10
'255'
>>> format(255, 'o') # base 8
'377'
>>> format(255, 'x') # base 16
'ff'