for / while else doesn't make sense

[Ben Bacarisse]

Mark Dickinson <mdickinson at enthought.com> writes:

> Ben Bacarisse <ben.usenet <at> bsb.me.uk> writes:
>> [1] Not being a Python expert I don't know how you show that actual
>> value of a float.  What is the Pythonic way to do that?
>
> I don't know about Pythonic, but here are some options.
>
> 1. Convert the float to Decimal, and print the result. This shows
>    the exact binary value that's stored, but displays it in decimal.
>    Be aware that the result will be hundreds of digits long for
>    very large or very small floats.
>
>    >>> print(Decimal(pi))
>    3.141592653589793115997963468544185161590576171875
>
> 2. If you're happy with a hexadecimal representation, use the
>    float.hex method. Again, this shows the exact value stored.
>
>    >>> print(pi.hex())
>    0x1.921fb54442d18p+1
>
> 3. To get an equivalent fraction, convert to the fractions.Fraction
>    type or use the as_integer_ratio method.
>
>    >>> from fractions import Fraction
>    >>> print(Fraction(pi))
>    884279719003555/281474976710656
>    >>> print(pi.as_integer_ratio())
>    (884279719003555, 281474976710656)

Thanks.

I worked out 1 and 3 after posting but I was not aware of how to get 2
in Python.  It's the format I am most familiar with (and it's very
compact for numbers that are anything but in decimal or as fractions)
so that's handy.

Once you told me that hex() does the trick I wondered if "%x" % 3.4
would give me 0x1.b333333333333p+1 but the float is converted to the
expected integer.  I doubt anyone relies on using %x for the integer
part of a float so maybe %x could be provided for floats...

-- 
Ben.