JavaScript toString(16) in Python for floats?

Question

I am trying to convert the following JavaScript code to Python:

var n = 0.3846705659431655
n.toString(16)

result: "0.6279c52c75af6"

The challenge I am having right now is that I can't seem to convert floats in Python. It will error on me or give me a different result.

Example:

n = 0.3846705659431655
float.hex(n)

result: 0x1.89e714b1d6bd8p-2
expected result: "0.6279c52c75af6"

Is there any other method for me to get the same result in Python?

Answer 1

I'm doing it with Python 3.8 but it should work also for you.

def FloatToHex(number, base = 16):
    if number < 0:                          # Check if the number is negative to manage the sign
        sign = "-"                          # Set the negative sign, it will be used later to generate the first element of the result list
        number = -number                    # Change the number sign to positive
    else:
        sign = ""                           # Set the positive sign, it will be used later to generate the first element of the result list

    s = [sign + str(int(number)) + '.']     # Generate the list, the first element will be the integer part of the input number
    number -= int(number)                   # Remove the integer part from the number

    for i in range(base):                   # Iterate N time where N is the required base
        y = int(number * 16)                # Multiply the number by 16 and take the integer part
        s.append(hex(y)[2:])                # Append to the list the hex value of y, the result is in format 0x00 so we take the value from postion 2 to the end
        number = number * 16 - y            # Calculate the next number required for the conversion

    return ''.join(s).rstrip('0')           # Join all the list values and return the converted number

n = 0.3846705659431655
print(FloatToHex(n))

result 0.6279c52c75af6