wrong precision in float formatting or doc error

[hagen]

BPO	3404
Nosy	@birkenfeld

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

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GitHub fields:

assignee = 'https://github.com/birkenfeld'
closed_at = <Date 2008-07-18.11:15:17.931>
created_at = <Date 2008-07-18.10:40:25.849>
labels = ['interpreter-core', 'docs']
title = 'wrong precision in float formatting or doc error'
updated_at = <Date 2008-07-18.11:15:17.901>
user = 'https://bugs.python.org/hagen'

bugs.python.org fields:

activity = <Date 2008-07-18.11:15:17.901>
actor = 'georg.brandl'
assignee = 'georg.brandl'
closed = True
closed_date = <Date 2008-07-18.11:15:17.931>
closer = 'georg.brandl'
components = ['Documentation', 'Interpreter Core']
creation = <Date 2008-07-18.10:40:25.849>
creator = 'hagen'
dependencies = []
files = []
hgrepos = []
issue_num = 3404
keywords = []
message_count = 3.0
messages = ['69947', '69948', '69949']
nosy_count = 2.0
nosy_names = ['georg.brandl', 'hagen']
pr_nums = []
priority = 'normal'
resolution = 'fixed'
stage = None
status = 'closed'
superseder = None
type = None
url = 'https://bugs.python.org/issue3404'
versions = ['Python 2.6', 'Python 3.0']

[hagen]

This seems to be wrong:

>>> "{0:.2}".format(1.2345)
'1.2'

The same happens for format specifiers "g" and "n", but not for "f":

>>> "{0:.2f}".format(1.2345)
'1.23'

With empty format specifier it can even get really wrong:

>>> "{0:.1}".format(1.2345)
'1.0'

[hagen]

Just found it documented for the % operator: There precision is number
of digits before and after decimal point for format "g".

But then the documentation for 2.6 is wrong:

"The precision is a decimal number indicating how many digits should be
displayed after the decimal point for a floating point value."

[birkenfeld]

Fixed docs in r65099.