#!/usr/bin/env python2.7

# Copyright 2014 Brett Slatkin, Pearson Education Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

# Preamble to mimick book environment
import logging
from pprint import pprint
from sys import stdout as STDOUT


# Example 19
class MyReturn(Exception):
    def __init__(self, value):
        self.value = value

def delegated():
    yield 1
    raise MyReturn(2)  # return 2 in Python 3
    yield 'Not reached'

def composed():
    try:
        for value in delegated():
            yield value
    except MyReturn as e:
        output = e.value
    yield output * 4

print list(composed())