Source code for bokeh.application.handlers.code_runner
#-----------------------------------------------------------------------------
# Copyright (c) 2012 - 2018, Anaconda, Inc. All rights reserved.
#
# Powered by the Bokeh Development Team.
#
# The full license is in the file LICENSE.txt, distributed with this software.
#-----------------------------------------------------------------------------
''' Provide a utility class ``CodeRunner`` for use by handlers that execute
Python source code.
'''
#-----------------------------------------------------------------------------
# Boilerplate
#-----------------------------------------------------------------------------
from __future__ import absolute_import, division, print_function, unicode_literals
import logging
log = logging.getLogger(__name__)
#-----------------------------------------------------------------------------
# Imports
#-----------------------------------------------------------------------------
# Standard library imports
import os
import sys
import traceback
from types import ModuleType
# External imports
# Bokeh imports
from ...util.serialization import make_id
#-----------------------------------------------------------------------------
# Globals and constants
#-----------------------------------------------------------------------------
__all__ = (
'CodeRunner',
)
#-----------------------------------------------------------------------------
# General API
#-----------------------------------------------------------------------------
#-----------------------------------------------------------------------------
# Dev API
#-----------------------------------------------------------------------------
[docs]class CodeRunner(object):
''' Compile and run Python source code.
'''
[docs] def __init__(self, source, path, argv):
'''
Args:
source (str) : python source code
path (str) : a filename to use in any debugging or error output
argv (list[str]) : a list of string arguments to make available
as ``sys.argv`` when the code executes
'''
self._permanent_error = None
self._permanent_error_detail = None
self.reset_run_errors()
import ast
self._code = None
try:
nodes = ast.parse(source, path)
self._code = compile(nodes, filename=path, mode='exec', dont_inherit=True)
except SyntaxError as e:
import traceback
self._code = None
self._permanent_error = ("Invalid syntax in \"%s\" on line %d:\n%s" % (os.path.basename(e.filename), e.lineno, e.text))
self._permanent_error_detail = traceback.format_exc()
self._path = path
self._source = source
self._argv = argv
self.ran = False
# Properties --------------------------------------------------------------
@property
def error(self):
''' If code execution fails, may contain a related error message.
'''
return self._error if self._permanent_error is None else self._permanent_error
@property
def error_detail(self):
''' If code execution fails, may contain a traceback or other details.
'''
return self._error_detail if self._permanent_error_detail is None else self._permanent_error_detail
@property
def failed(self):
''' ``True`` if code execution failed
'''
return self._failed or self._code is None
@property
def path(self):
''' The path that new modules will be configured with.
'''
return self._path
@property
def source(self):
''' The configured source code that will be executed when ``run`` is
called.
'''
return self._source
# Public methods ----------------------------------------------------------
[docs] def new_module(self):
''' Make a fresh module to run in.
Returns:
Module
'''
self.reset_run_errors()
if self._code is None:
return None
module_name = 'bk_script_' + make_id().replace('-', '')
module = ModuleType(str(module_name)) # str needed for py2.7
module.__dict__['__file__'] = os.path.abspath(self._path)
return module
[docs] def reset_run_errors(self):
''' Clears any transient error conditions from a previous run.
Returns
None
'''
self._failed = False
self._error = None
self._error_detail = None
[docs] def run(self, module, post_check):
''' Execute the configured source code in a module and run any post
checks.
Args:
module (Module) : a module to execute the configured code in.
post_check(callable) : a function that can raise an exception
if expected post-conditions are not met after code execution.
'''
try:
# Simulate the sys.path behaviour decribed here:
#
# https://docs.python.org/2/library/sys.html#sys.path
_cwd = os.getcwd()
_sys_path = list(sys.path)
_sys_argv = list(sys.argv)
sys.path.insert(0, os.path.dirname(self._path))
sys.argv = [os.path.basename(self._path)] + self._argv
exec(self._code, module.__dict__)
post_check()
except Exception as e:
self._failed = True
self._error_detail = traceback.format_exc()
_exc_type, _exc_value, exc_traceback = sys.exc_info()
filename, line_number, func, txt = traceback.extract_tb(exc_traceback)[-1]
self._error = "%s\nFile \"%s\", line %d, in %s:\n%s" % (str(e), os.path.basename(filename), line_number, func, txt)
finally:
# undo sys.path, CWD fixups
os.chdir(_cwd)
sys.path = _sys_path
sys.argv = _sys_argv
self.ran = True
#-----------------------------------------------------------------------------
# Private API
#-----------------------------------------------------------------------------
#-----------------------------------------------------------------------------
# Code
#-----------------------------------------------------------------------------