sys

This module provides access to some objects used or maintained by the interpreter and to functions that interact strongly with the interpreter.

Dynamic objects:

argv – command line arguments; argv[0] is the script pathname if known path – module search path; path[0] is the script directory, else ‘’ modules – dictionary of loaded modules

displayhook – called to show results in an interactive session excepthook – called to handle any uncaught exception other than SystemExit

To customize printing in an interactive session or to install a custom top-level exception handler, assign other functions to replace these.
exitfunc – if sys.exitfunc exists, this routine is called when Python exits
Assigning to sys.exitfunc is deprecated; use the atexit module instead.

stdin – standard input file object; used by raw_input() and input() stdout – standard output file object; used by the print statement stderr – standard error object; used for error messages

By assigning other file objects (or objects that behave like files) to these, it is possible to redirect all of the interpreter’s I/O.

last_type – type of last uncaught exception last_value – value of last uncaught exception last_traceback – traceback of last uncaught exception

These three are only available in an interactive session after a traceback has been printed.

exc_type – type of exception currently being handled exc_value – value of exception currently being handled exc_traceback – traceback of exception currently being handled

The function exc_info() should be used instead of these three, because it is thread-safe.

Static objects:

float_info – a dict with information about the float inplementation. long_info – a struct sequence with information about the long implementation. maxint – the largest supported integer (the smallest is -maxint-1) maxsize – the largest supported length of containers. maxunicode – the largest supported character builtin_module_names – tuple of module names built into this interpreter version – the version of this interpreter as a string version_info – version information as a named tuple hexversion – version information encoded as a single integer copyright – copyright notice pertaining to this interpreter platform – platform identifier executable – absolute path of the executable binary of the Python interpreter prefix – prefix used to find the Python library exec_prefix – prefix used to find the machine-specific Python library float_repr_style – string indicating the style of repr() output for floats __stdin__ – the original stdin; don’t touch! __stdout__ – the original stdout; don’t touch! __stderr__ – the original stderr; don’t touch! __displayhook__ – the original displayhook; don’t touch! __excepthook__ – the original excepthook; don’t touch!

Functions:

displayhook() – print an object to the screen, and save it in __builtin__._ excepthook() – print an exception and its traceback to sys.stderr exc_info() – return thread-safe information about the current exception exc_clear() – clear the exception state for the current thread exit() – exit the interpreter by raising SystemExit getdlopenflags() – returns flags to be used for dlopen() calls getprofile() – get the global profiling function getrefcount() – return the reference count for an object (plus one :-) getrecursionlimit() – return the max recursion depth for the interpreter getsizeof() – return the size of an object in bytes gettrace() – get the global debug tracing function setcheckinterval() – control how often the interpreter checks for events setdlopenflags() – set the flags to be used for dlopen() calls setprofile() – set the global profiling function setrecursionlimit() – set the max recursion depth for the interpreter settrace() – set the global debug tracing function

Functions

call_tracing((func, args) -> object) Call func(*args), while tracing is enabled.
callstats(() -> tuple of integers) Return a tuple of function call statistics, if CALL_PROFILE was defined when Python was built.
displayhook((object) -> None) Print an object to sys.stdout and also save it in __builtin__._
exc_clear(() -> None) Clear global information on the current exception.
exc_info() -> (type, value, traceback) Return information about the most recent exception caught by an except clause in the current stack frame or in an older stack frame.
excepthook((exctype, value, traceback) -> None) Handle an exception by displaying it with a traceback on sys.stderr.
exit([status]) Exit the interpreter by raising SystemExit(status).
exitfunc() run any registered exit functions
getcheckinterval(...)
getdefaultencoding(() -> string) Return the current default string encoding used by the Unicode implementation.
getdlopenflags(() -> int) Return the current value of the flags that are used for dlopen calls.
getfilesystemencoding(() -> string) Return the encoding used to convert Unicode filenames in operating system filenames.
getprofile() Return the profiling function set with sys.setprofile.
getrecursionlimit() Return the current value of the recursion limit, the maximum depth of the Python interpreter stack.
getrefcount((object) -> integer) Return the reference count of object.
getsizeof((object, default) -> int) Return the size of object in bytes.
gettrace() Return the global debug tracing function set with sys.settrace.
setcheckinterval(n) Tell the Python interpreter to check for asynchronous events every n instructions.
setdlopenflags((n) -> None) Set the flags used by the interpreter for dlopen calls, such as when the interpreter loads extension modules.
setprofile(function) Set the profiling function.
setrecursionlimit(n) Set the maximum depth of the Python interpreter stack to n.
settrace(function) Set the global debug tracing function.

Exceptions

exc_type