iSharkFly-Open
/
python-peps
mirror of https://github.com/python/peps.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Spell checked.

This commit is contained in:
Barry Warsaw 2015-09-05 13:50:27 -04:00
parent 55d84e727c
commit 3732c04a7a
1 changed files with 5 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
pep-0498.txt
View File

@ -18,7 +18,7 @@ Python supports multiple ways to format text strings. These include
[#]_. Each of these methods have their advantages, but in addition [#]_. Each of these methods have their advantages, but in addition
have disadvantages that make them cumbersome to use in practice. This have disadvantages that make them cumbersome to use in practice. This
PEP proposed to add a new string formatting mechanism: Literal String PEP proposed to add a new string formatting mechanism: Literal String
Interpolation. In this PEP, such strings will be refered to as Interpolation. In this PEP, such strings will be referred to as
"f-strings", taken from the leading character used to denote such "f-strings", taken from the leading character used to denote such
strings, and standing for "formatted strings". strings, and standing for "formatted strings".
@ -212,7 +212,7 @@ that applies to ``str``, not to the type of the expression.
Similar to ``str.format()``, optional format specifiers maybe be Similar to ``str.format()``, optional format specifiers maybe be
included inside the f-string, separated from the expression (or the included inside the f-string, separated from the expression (or the
type conversion, if specified) by a colon. If a format specifier is type conversion, if specified) by a colon. If a format specifier is
not provied, an empty string is used. not provided, an empty string is used.
So, an f-string looks like:: So, an f-string looks like::
@ -223,7 +223,7 @@ format specifier. The resulting value is used when building the value
of the f-string. of the f-string.
Expressions cannot contain ``':'`` or ``'!'`` outside of strings or Expressions cannot contain ``':'`` or ``'!'`` outside of strings or
parens, brackets, or braces. The exception is that the ``'!='`` parentheses, brackets, or braces. The exception is that the ``'!='``
operator is allowed as a special case. operator is allowed as a special case.
Escape sequences Escape sequences
@ -437,7 +437,7 @@ How to denote f-strings
Because the compiler must be involved in evaluating the expressions Because the compiler must be involved in evaluating the expressions
contained in the interpolated strings, there must be some way to contained in the interpolated strings, there must be some way to
denote to the compiler which strings should be evaluated. This PEP denote to the compiler which strings should be evaluated. This PEP
chose a leading ``'f'`` character preceeding the string literal. This chose a leading ``'f'`` character preceding the string literal. This
is similar to how ``'b'`` and ``'r'`` prefixes change the meaning of is similar to how ``'b'`` and ``'r'`` prefixes change the meaning of
the string itself, at compile time. Other prefixes were suggested, the string itself, at compile time. Other prefixes were suggested,
such as ``'i'``. No option seemed better than the other, so ``'f'`` such as ``'i'``. No option seemed better than the other, so ``'f'``
@ -621,7 +621,7 @@ expression is seen and is syntactically invalid. As there's no
practical use for a plain lambda in an f-string expression, this is practical use for a plain lambda in an f-string expression, this is
not seen as much of a limitation. not seen as much of a limitation.
If you feel you must use lambdas, they may be used inside of parens:: If you feel you must use lambdas, they may be used inside of parentheses::
>>> f'{(lambda x: x*2)(3)}' >>> f'{(lambda x: x*2)(3)}'
'6' '6'