def something_about_bases(number, bonus=False):
    assert isinstance(number, str)
 
    a = -ord('a') + 10
    nums = [ord(n) + a if n.isalpha() else int(n) for n in number]
 
    smallest_base = max(nums) + 1
    top_base = 16 if bonus else smallest_base
 
    for base in range(smallest_base, top_base + 1):
        val = sum(n * base ** (len(nums) - i - 1) for i, n in enumerate(nums))
        print("base %i => %i" % (base, val))
 
inputs = ['1', '21', 'ab3', 'ff']
for i in inputs:
    something_about_bases(i)
 
# bonus 1
print('')
something_about_bases('21', bonus=True)
 
# bonus 2
print('')
something_about_bases('0')

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