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From: MRAB <python@mrabarnett.plus.com>
Newsgroups: comp.lang.python
Subject: Re[2]: .format won't display my value with 2 decimal places: Why?
Date: Mon, 25 Jan 2016 17:19:46 +0000
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On 2016-01-25 16:51:36, "Ian Kelly" <ian.g.kelly@gmail.com> wrote:

>On Sun, Jan 24, 2016 at 2:20 PM, MRAB <python@mrabarnett.plus.com>=20
>wrote:
>>  The format method, on the other hand, belongs to the format string=20
>>it's
>>  attached to. In this example:
>>
>>      'The new price is {}' .format(newPrice, '.2f')
>>
>>  the format string is 'The new price is {}' and you're calling its=20
>>'format'
>>  method with 2 values for that string, the first being 4.0 (used) and=
=20
>>the
>>  second on being '.2f' (unused).
>>
>>  What you want is:
>>
>>      print('The new price is {:.2f}'.format(newPrice))
>
>Why doesn't str.format raise an exception when passed extra positional
>arguments?
>
That format string uses auto-numbering, and it's equivalent to 'The new=20
price is {0:.2f}'.

In general, the positional arguments can be used in any order, and there=
=20
can also be keyword arguments, so it would need to remember which=20
arguments had been used. Would it be worth it?

Do you really want to insist that the format string always used _all_ of=
=20
the arguments?