Program to Compute the Binary representation of FLOATING-POINT numbers

def float_bin(num):
    str_num = str(num)
    index_deci = str_num.find('.')
    float_num = float(str_num[(index_deci):])

    res_int_num = bin(int(num))
    res_float_num, i = ".", 0

    while bool(float_num):
        if i < 8:
            res = float_num*2
            res_float_num += str(int(res))

            str_res = str(res)
            index_deci = str_res.find('.')
            float_num = float(str_res[(index_deci):])

            i += 1
        else:
            break

    return res_int_num+res_float_num

var = float_bin(2.77)
print(var)