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Diffstat (limited to 'Doc/library/sys.rst')
| -rw-r--r-- | Doc/library/sys.rst | 39 |
1 files changed, 26 insertions, 13 deletions
diff --git a/Doc/library/sys.rst b/Doc/library/sys.rst index 3997627..e812b85 100644 --- a/Doc/library/sys.rst +++ b/Doc/library/sys.rst @@ -53,6 +53,13 @@ always available. ``modules.keys()`` only lists the imported modules.) +.. function:: call_tracing(func, args) + + Call ``func(*args)``, while tracing is enabled. The tracing state is saved, + and restored afterwards. This is intended to be called from a debugger from + a checkpoint, to recursively debug some other code. + + .. data:: copyright A string containing the copyright pertaining to the Python interpreter. @@ -219,19 +226,25 @@ always available. Exit from Python. This is implemented by raising the :exc:`SystemExit` exception, so cleanup actions specified by finally clauses of :keyword:`try` - statements are honored, and it is possible to intercept the exit attempt at an - outer level. The optional argument *arg* can be an integer giving the exit - status (defaulting to zero), or another type of object. If it is an integer, - zero is considered "successful termination" and any nonzero value is considered - "abnormal termination" by shells and the like. Most systems require it to be in - the range 0-127, and produce undefined results otherwise. Some systems have a - convention for assigning specific meanings to specific exit codes, but these are - generally underdeveloped; Unix programs generally use 2 for command line syntax - errors and 1 for all other kind of errors. If another type of object is passed, - ``None`` is equivalent to passing zero, and any other object is printed to - ``sys.stderr`` and results in an exit code of 1. In particular, - ``sys.exit("some error message")`` is a quick way to exit a program when an - error occurs. + statements are honored, and it is possible to intercept the exit attempt at + an outer level. + + The optional argument *arg* can be an integer giving the exit status + (defaulting to zero), or another type of object. If it is an integer, zero + is considered "successful termination" and any nonzero value is considered + "abnormal termination" by shells and the like. Most systems require it to be + in the range 0-127, and produce undefined results otherwise. Some systems + have a convention for assigning specific meanings to specific exit codes, but + these are generally underdeveloped; Unix programs generally use 2 for command + line syntax errors and 1 for all other kind of errors. If another type of + object is passed, ``None`` is equivalent to passing zero, and any other + object is printed to :data:`stderr` and results in an exit code of 1. In + particular, ``sys.exit("some error message")`` is a quick way to exit a + program when an error occurs. + + Since :func:`exit` ultimately "only" raises an exception, it will only exit + the process when called from the main thread, and the exception is not + intercepted. .. data:: exitfunc |