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(python2.1-lib.info)RExec Objects

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RExec Objects
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`RExec' instances support the following methods:

`r_eval(code)'
     CODE must either be a string containing a Python expression, or a
     compiled code object, which will be evaluated in the restricted
     environment's `__main__' module.  The value of the expression or
     code object will be returned.

`r_exec(code)'
     CODE must either be a string containing one or more lines of
     Python code, or a compiled code object, which will be executed in
     the restricted environment's `__main__' module.

`r_execfile(filename)'
     Execute the Python code contained in the file FILENAME in the
     restricted environment's `__main__' module.

Methods whose names begin with `s_' are similar to the functions
beginning with `r_', but the code will be granted access to restricted
versions of the standard I/O streams `sys.stdin', `sys.stderr', and
`sys.stdout'.

`s_eval(code)'
     CODE must be a string containing a Python expression, which will
     be evaluated in the restricted environment.

`s_exec(code)'
     CODE must be a string containing one or more lines of Python code,
     which will be executed in the restricted environment.

`s_execfile(code)'
     Execute the Python code contained in the file FILENAME in the
     restricted environment.

`RExec' objects must also support various methods which will be
implicitly called by code executing in the restricted environment.
Overriding these methods in a subclass is used to change the policies
enforced by a restricted environment.

`r_import(modulename[, globals[, locals[, fromlist]]])'
     Import the module MODULENAME, raising an `ImportError' exception
     if the module is considered unsafe.

`r_open(filename[, mode[, bufsize]])'
     Method called when `open()' is called in the restricted
     environment.  The arguments are identical to those of `open()',
     and a file object (or a class instance compatible with file
     objects) should be returned.  `RExec''s default behaviour is allow
     opening any file for reading, but forbidding any attempt to write
     a file.  See the example below for an implementation of a less
     restrictive `r_open()'.

`r_reload(module)'
     Reload the module object MODULE, re-parsing and re-initializing it.

`r_unload(module)'
     Unload the module object MODULE (i.e., remove it from the
     restricted environment's `sys.modules' dictionary).

And their equivalents with access to restricted standard I/O streams:

`s_import(modulename[, globals[, locals[, fromlist]]])'
     Import the module MODULENAME, raising an `ImportError' exception
     if the module is considered unsafe.

`s_reload(module)'
     Reload the module object MODULE, re-parsing and re-initializing it.

`s_unload(module)'
     Unload the module object MODULE.