string formatting: engineering notation

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?

Thanks,
Darren

re: string formatting: engineering notation

Darren Dale wrote:How close is this:
'3.142e+00'

regards
Steve
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re: string formatting: engineering notation

Steve Holden wrote:
'3.142e+04'

What I am looking for is '31.4159e+03'

Darren

re: string formatting: engineering notation

On 2007-03-14, Steve Holden <steve@holdenweb.comwrote:Not close at all. It should be "3.14159"
'3.142e+01'

should be 31.4159
'3.142e+02'

should be 314.159
'3.142e+04'

should be 31.4159e3

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re: string formatting: engineering notation

Steve Holden <steve@holdenweb.comwrites:
'3.142e+05'Not close when you have the exponent.



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re: string formatting: engineering notation

On Mar 14, 1:14 pm, Darren Dale <d...@cornell.eduwrote:
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

re: string formatting: engineering notation

attn.steven.kuo@gmail.com wrote:
That's a good suggestion. It's probably fast enough. I was hoping that
something like '%n'%my_number already existed.