issue_server101.py 文件源码

def _import(name, filename=None):
    """
    Run the given callable in a 'sandboxed' environment.
    Currently, this includes saving and restoring the contents of
    sys and __builtins__; and suppressing stdin, stdout, and stderr.
    """
    # Note that we just do a shallow copy of sys.  In particular,
    # any changes made to sys.modules will be kept.  But we do
    # explicitly store sys.path.
    old_sys = sys.__dict__.copy()
    old_sys_path = sys.path[:]
    old_builtins = __builtin__.__dict__.copy()

    # Add the current directory to sys.path, in case they're trying to
    # import a module by name that resides in the current directory.
    # But add it to the end -- otherwise, the explicit directory added
    # in get_value_from_filename might get overwritten
    sys.path.append('')

    # Suppress input and output.  (These get restored when we restore
    # sys to old_sys).  
    sys.stdin = sys.stdout = sys.stderr = _dev_null
    sys.__stdin__ = sys.__stdout__ = sys.__stderr__ = _dev_null

    # Remove any command-line arguments
    sys.argv = ['(imported)']

    try:
        try:
            if filename is None:
                return __import__(name)
            else:
                # For importing scripts:
                return imp.load_source(name, filename)
        except KeyboardInterrupt: raise
        except:
            exc_typ, exc_val, exc_tb = sys.exc_info()
            if exc_val is None:
                estr = '%s' % (exc_typ,)
            else:
                estr = '%s: %s' % (exc_typ.__name__, exc_val)
            if exc_tb.tb_next is not None:
                estr += ' (line %d)' % (exc_tb.tb_next.tb_lineno,)
            raise ImportError(estr)
    finally:
        # Restore the important values that we saved.
        __builtin__.__dict__.clear()
        __builtin__.__dict__.update(old_builtins)
        sys.__dict__.clear()
        sys.__dict__.update(old_sys)
        sys.path = old_sys_path