string formatting: engineering notation

[attn.steven.kuo at gmail.com]

On Mar 14, 1:14 pm, Darren Dale <d... at cornell.edu> wrote:
> Does anyone know if it is possible to represent a number as a string with
> engineering notation (like scientific notation, but with 10 raised to
> multiples of 3: 120e3, 12e-6, etc.). I know this is possible with the
> decimal.Decimal class, but repeatedly instantiating Decimals is inefficient
> for my application (matplotlib plotting library). If it is not currently
> possible, do you think the python devs would be receptive to including
> support for engineering notation in future releases?


Do you also consider this to be too inefficient?


import math

for exponent in xrange(-10, 11):
    flt = 1.23 * math.pow(10, exponent)
    l = math.log10(flt)
    if l < 0:
        l = l - 3
    p3 = int(l / 3) * 3
    multiplier = flt / pow(10, p3)
    print '%e => %fe%d' % (flt, multiplier, p3)

--
Hope this helps,
Steven