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  r78760 | georg.brandl | 2010-03-07 16:23:59 +0100 (So, 07 Mär 2010) | 1 line

  #5341: more built-in vs builtin fixes.
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  r78771 | georg.brandl | 2010-03-07 21:58:31 +0100 (So, 07 Mär 2010) | 1 line

  #8085: The function is called PyObject_NewVar, not PyObject_VarNew.
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  r78772 | georg.brandl | 2010-03-07 22:12:28 +0100 (So, 07 Mär 2010) | 1 line

  #8039: document conditional expressions better, giving them their own section.
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  r78773 | georg.brandl | 2010-03-07 22:32:06 +0100 (So, 07 Mär 2010) | 1 line

  #8044: document Py_{Enter,Leave}RecursiveCall functions.
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  r78802 | georg.brandl | 2010-03-08 17:28:40 +0100 (Mo, 08 Mär 2010) | 1 line

  Fix typo.
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  r78922 | georg.brandl | 2010-03-13 14:41:58 +0100 (Sa, 13 Mär 2010) | 1 line

  Update for new download location.
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  r78952 | georg.brandl | 2010-03-14 10:55:08 +0100 (So, 14 Mär 2010) | 1 line

  #8137: add iso-8859-16 to the standard encodings table.
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This commit is contained in:
Georg Brandl 2010-03-14 10:56:14 +00:00
parent c0e22b7889
commit 93dc9eb2a3
10 changed files with 114 additions and 65 deletions
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35
Doc/reference/expressions.rst
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@ -1113,12 +1113,7 @@ Boolean operations
pair: Conditional; expression
pair: Boolean; operation
Boolean operations have the lowest priority of all Python operations:
.. productionlist::
expression: `conditional_expression` | `lambda_form`
expression_nocond: `or_test` | `lambda_form_nocond`
conditional_expression: `or_test` ["if" `or_test` "else" `expression`]
or_test: `and_test` | `or_test` "or" `and_test`
and_test: `not_test` | `and_test` "and" `not_test`
not_test: `comparison` | "not" `not_test`
@ -1135,10 +1130,6 @@ truth value by providing a :meth:`__bool__` method.
The operator :keyword:`not` yields ``True`` if its argument is false, ``False``
otherwise.
The expression ``x if C else y`` first evaluates *C* (*not* *x*); if *C* is
true, *x* is evaluated and its value is returned; otherwise, *y* is evaluated
and its value is returned.
.. index:: operator: and
The expression ``x and y`` first evaluates *x*; if *x* is false, its value is
@ -1158,6 +1149,30 @@ not bother to return a value of the same type as its argument, so e.g., ``not
'foo'`` yields ``False``, not ``''``.)
Conditional Expressions
=======================
.. versionadded:: 2.5
.. index::
pair: conditional; expression
pair: ternary; operator
.. productionlist::
conditional_expression: `or_test` ["if" `or_test` "else" `expression`]
expression: `conditional_expression` | `lambda_form`
expression_nocond: `or_test` | `lambda_form_nocond`
Conditional expressions (sometimes called a "ternary operator") have the lowest
priority of all Python operations.
The expression ``x if C else y`` first evaluates the condition, *C* (*not* *x*);
if *C* is true, *x* is evaluated and its value is returned; otherwise, *y* is
evaluated and its value is returned.
See :pep:`308` for more details about conditional expressions.
.. _lambdas:
.. _lambda:
@ -1252,6 +1267,8 @@ groups from right to left).
+===============================================+=====================================+
| :keyword:`lambda` | Lambda expression |
+-----------------------------------------------+-------------------------------------+
| :keyword:`if` -- :keyword:`else` | Conditional expression |
+-----------------------------------------------+-------------------------------------+
| :keyword:`or` | Boolean OR |
+-----------------------------------------------+-------------------------------------+
| :keyword:`and` | Boolean AND |