get rid of scientific notation of str() for float

gistfile1.py

def float2str(val):
        val, sci, exp = str(val).partition('e')
        if not sci:
                return val
        sign = ''
        if val[0] in '-':
                sign = '-'
                val = val[1:]
        assert val.count('.') == 1 and val[1] == '.' and val[0] != '0'
        val = val[0] + val[2:]
        esign, exp = exp[0], int(exp[1:])
        if esign == '-':
                zeros = exp - 1
                val = '0.' + (zeros * '0') + val
        elif esign == '+':
                zeros = exp - (len(val) - 1)
                assert zeros >= 0
                val = val + (zeros * '0') + '.0'
        return sign + val

if __name__ == '__main__':
        assert float2str(0.0000001234567891) == '0.0000001234567891'
        assert float2str(-0.0000001234567891) == '-0.0000001234567891'
        assert float2str(12345678492769024.) == '12345678492769024.0'
        assert float2str(123456784927690241.) == '123456784927690240.0'
        assert float2str(-12345678492769024.) == '-12345678492769024.0'
        assert float2str(-123456784927690241.) == '-123456784927690240.0'

Thanks to pyrtsa for figuring out that this can be done much easier with:
format(Decimal(str(val)), 'f')