如何将浮点十进制转换为浮点八进制/二进制？

Question

I have been searched everywhere to find a way to convert float to octal or binary. I know about the float.hex and float.fromhex . Is theres a modules which can do the same work for octal/binary values?

For example: I have a float 12.325 and I should get float octal 14.246 . Tell me, how I can do this? Thanks in advance.

Answer 1

You could write your own, if you only care about three decimal places then set n to 3:

def frac_to_oct(f, n=4):
    # store the number before the decimal point
    whole = int(f)
    rem = (f - whole) * 8
    int_ = int(rem)
    rem = (rem - int_) * 8
    octals = [str(int_)]
    count = 1
    # loop until 8 * rem gives you a whole num or n times
    while rem and count < n:
        count += 1
        int_ = int(rem)
        rem = (rem - int_) * 8
        octals.append(str(int_))
    return float("{:o}.{}".format(whole, "".join(octals)))

Using your input 12.325 :

In [9]: frac_to_oct(12.325)
Out[9]: 14.2463
In [10]: frac_to_oct(121212.325, 4)
Out[10]: 354574.2463

In [11]: frac_to_oct(0.325, 4)
Out[11]: 0.2463
In [12]: frac_to_oct(2.1, 4)
Out[12]: 2.0631
In [13]:  frac_to_oct(0)
Out[13]: 0.0
In [14]:  frac_to_oct(33)
Out[14]: 41.0

Answer 2

Here's the solution, explanation below:

def ToLessThanOne(num): # Change "num" into a decimal <1
    while num > 1:
        num /= 10
    return num

def FloatToOctal(flo, places=8): # Flo is float, places is octal places
    main, dec = str(flo).split(".") # Split into Main (integer component)
                                    # and Dec (decimal component)
    main, dec = int(main), int(dec) # Turn into integers

    res = oct(main)[2::]+"." # Turn the integer component into an octal value
                             # while removing the "ox" that would normally appear ([2::])
                             # Also, res means result

    # NOTE: main and dec are being recycled here

    for x in range(places): 
        main, dec = str((ToLessThanOne(dec))*8).split(".") # main is integer octal
                                                           # component
                                                           # dec is octal point
                                                           # component
        dec = int(dec) # make dec an integer

        res += main # Add the octal num to the end of the result

    return res # finally return the result

So you can do print(FloatToOctal(12.325)) and it shall print out 14.246314631

Finally, if you want less octal places (decimal places but in octal) simply add the places argument: print(FloatToOctal(12.325, 3)) which returns 14.246 as is correct according to this website: http://coderstoolbox.net/number/