simple string format question

[Neal Becker]

Is there a way to specify to format I want a floating point written with no more
than e.g., 2 digits after the decimal? I tried {:.2f}, but then I get all
floats written with 2 digits, even if they are 0:

2.35 << yes, that's what I want
2.00 << no, I want just 2 or 2.

[Chris Rebert]

Not that I can find. Seems you'll have to implement it yourself.


In the event that your project uses Django, there happens to be a
template tag for this (pass it -2 in your case):
https://docs.djangoproject.com/en/dev/ref/templates/builtins/?from=olddocs#floatformat

Cheers,
Chris

[Adrien]

Le 15/10/2012 14:12, Neal Becker a écrit :
> Is there a way to specify to format I want a floating point written with no more
> than e.g., 2 digits after the decimal? I tried {:.2f}, but then I get all
> floats written with 2 digits, even if they are 0:
>
> 2.35 << yes, that's what I want
> 2.00 << no, I want just 2 or 2.

Maybe you're looking for "{:.3g}"

print "{:.3g}".format(2)
# '2'

print "{:.3g}".format(2.00)
# '2'

print "{:.3g}".format(2.35)
# '2.35'

print "{:.3g}".format(2.356) # this rounds up
# '2.36'

Cheers,

-- Adrien

[Dave Angel]

On 10/15/2012 08:29 AM, Chris Rebert wrote:
> On Mon, Oct 15, 2012 at 5:12 AM, Neal Becker <ndbe...@gmail.com> wrote:

>> Is there a way to specify to format I want a floating point written with no more
>> than e.g., 2 digits after the decimal? I tried {:.2f}, but then I get all
>> floats written with 2 digits, even if they are 0:
>>
>> 2.35 << yes, that's what I want
>> 2.00 << no, I want just 2 or 2.

> Not that I can find. Seems you'll have to implement it yourself.

To do it yourself, probably best to use a temp string value, created by
format "{: f}". (Notice the space before the f, to reserve space for
the sign) Then, slice that value to length 4 . Finally, in your actual
format, use :5s for a format. This should add the blanks for padding,
so other columns still line up.

>
> In the event that your project uses Django, there happens to be a
> template tag for this (pass it -2 in your case):
> https://docs.djangoproject.com/en/dev/ref/templates/builtins/?from=olddocs#floatformat
>
> Cheers,
> Chris

--

DaveA

[Piet van Oostrum]

Adrien <adno...@gmail.com> writes:

> print "{:.3g}".format(2.356) # this rounds up

But:

>>> print "{:.3g}".format(12.356)
12.4
>>> print "{:.3g}".format(123.356)
123

--
Piet van Oostrum <pi...@vanoostrum.org>
WWW: http://pietvanoostrum.com/
PGP key: [8DAE142BE17999C4]

[Neil Cerutti]

On 2012-10-25, Piet van Oostrum <pi...@vanoostrum.org> wrote:
> Adrien <adno...@gmail.com> writes:
>
>> print "{:.3g}".format(2.356) # this rounds up
>
> But:
>
>>>> print "{:.3g}".format(12.356)
> 12.4
>>>> print "{:.3g}".format(123.356)
> 123

The precision is a decimal number indicating how many digits
should be displayed after the decimal point for a floating
point value formatted with 'f' and 'F', or before and after the
decimal point for a floating point value formatted with 'g' or
'G'. For non-number types the field indicates the maximum field
size - in other words, how many characters will be used from
the field content. The precision is not allowed for integer
values.

So g will print a specific number of significant digits, so it
won't do what Adrien wants.

And f will print a fixed number of digits after the decimal
point, so it won't do want Adrien wants.

Adrien, you will need to do some post-processing on fixed point
output to remove trailing zeroes.

>>> print("{:.2f}".format(2.1).rstrip('0'))
2.1
>>> print("{:.2f}".format(2.127).rstrip('0'))
2.13

--
Neil Cerutti