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| author | Raymond Hettinger <python@rcn.com> | 2010-12-17 20:19:50 (GMT) |
|---|---|---|
| committer | Raymond Hettinger <python@rcn.com> | 2010-12-17 20:19:50 (GMT) |
| commit | 09f44140aa317cb06f13f366fd27e19613375734 (patch) | |
| tree | ee70c018000115cef58865165180239752ded735 | |
| parent | 401edd69cf23f7f102aece55e05157daf1b87f9f (diff) | |
| download | cpython-09f44140aa317cb06f13f366fd27e19613375734.zip cpython-09f44140aa317cb06f13f366fd27e19613375734.tar.gz cpython-09f44140aa317cb06f13f366fd27e19613375734.tar.bz2 | |
Expand the LBYL glossary entry.
| -rw-r--r-- | Doc/glossary.rst | 6 | ||||
| -rw-r--r-- | Doc/whatsnew/3.2.rst | 2 |
2 files changed, 6 insertions, 2 deletions
diff --git a/Doc/glossary.rst b/Doc/glossary.rst index a051fe8..4958d3b 100644 --- a/Doc/glossary.rst +++ b/Doc/glossary.rst @@ -392,6 +392,12 @@ Glossary the :term:`EAFP` approach and is characterized by the presence of many :keyword:`if` statements. + In a multi-threaded environment, the LBYL approach can risk introducing a + race condition between "the looking" and "the leaping". For example, the + code, ``if key in mapping: return mapping[key]`` can fail if another + thread removes *key* from *mapping* after the test, but before the lookup. + This issue can be solved with locks or by using the EAFP approach. + list A built-in Python :term:`sequence`. Despite its name it is more akin to an array in other languages than to a linked list since access to diff --git a/Doc/whatsnew/3.2.rst b/Doc/whatsnew/3.2.rst index 488ad3b..bb3053d 100644 --- a/Doc/whatsnew/3.2.rst +++ b/Doc/whatsnew/3.2.rst @@ -112,8 +112,6 @@ Example of calling the parser on a command string:: >>> cmd = 'deploy sneezy.example.com sleepy.example.com -u skycaptain' >>> result = parser.parse_args(cmd.split()) - - >>> # parsed variables are stored in the attributes >>> result.action 'deploy' >>> result.targets |