| # (c) 2005 Ian Bicking and contributors; written for Paste (http://pythonpaste.org) |
| # Licensed under the MIT license: http://www.opensource.org/licenses/mit-license.php |
| from six.moves import cStringIO as StringIO |
| import traceback |
| import threading |
| import pdb |
| import six |
| import sys |
| |
| exec_lock = threading.Lock() |
| |
| class EvalContext(object): |
| |
| """ |
| Class that represents a interactive interface. It has its own |
| namespace. Use eval_context.exec_expr(expr) to run commands; the |
| output of those commands is returned, as are print statements. |
| |
| This is essentially what doctest does, and is taken directly from |
| doctest. |
| """ |
| |
| def __init__(self, namespace, globs): |
| self.namespace = namespace |
| self.globs = globs |
| |
| def exec_expr(self, s): |
| out = StringIO() |
| exec_lock.acquire() |
| save_stdout = sys.stdout |
| try: |
| debugger = _OutputRedirectingPdb(save_stdout) |
| debugger.reset() |
| pdb.set_trace = debugger.set_trace |
| sys.stdout = out |
| try: |
| code = compile(s, '<web>', "single", 0, 1) |
| six.exec_(code, self.globs, self.namespace) |
| debugger.set_continue() |
| except KeyboardInterrupt: |
| raise |
| except: |
| traceback.print_exc(file=out) |
| debugger.set_continue() |
| finally: |
| sys.stdout = save_stdout |
| exec_lock.release() |
| return out.getvalue() |
| |
| # From doctest |
| class _OutputRedirectingPdb(pdb.Pdb): |
| """ |
| A specialized version of the python debugger that redirects stdout |
| to a given stream when interacting with the user. Stdout is *not* |
| redirected when traced code is executed. |
| """ |
| def __init__(self, out): |
| self.__out = out |
| pdb.Pdb.__init__(self) |
| |
| def trace_dispatch(self, *args): |
| # Redirect stdout to the given stream. |
| save_stdout = sys.stdout |
| sys.stdout = self.__out |
| # Call Pdb's trace dispatch method. |
| try: |
| return pdb.Pdb.trace_dispatch(self, *args) |
| finally: |
| sys.stdout = save_stdout |
