removed 1st edition code

18-context-mngr/mirror_gen_exc.py

@@ -1,101 +0,0 @@
-"""
-A "mirroring" ``stdout`` context manager.
-
-While active, the context manager reverses text output to
-``stdout``::
-
-# tag::MIRROR_GEN_DEMO_1[]
-
-    >>> from mirror_gen import looking_glass
-    >>> with looking_glass() as what:  # <1>
-    ...      print('Alice, Kitty and Snowdrop')
-    ...      print(what)
-    ...
-    pordwonS dna yttiK ,ecilA
-    YKCOWREBBAJ
-    >>> what
-    'JABBERWOCKY'
-
-# end::MIRROR_GEN_DEMO_1[]
-
-
-This exposes the context manager operation::
-
-# tag::MIRROR_GEN_DEMO_2[]
-
-    >>> from mirror_gen import looking_glass
-    >>> manager = looking_glass()  # <1>
-    >>> manager  # doctest: +ELLIPSIS
-    <contextlib._GeneratorContextManager object at 0x...>
-    >>> monster = manager.__enter__()  # <2>
-    >>> monster == 'JABBERWOCKY'  # <3>
-    eurT
-    >>> monster
-    'YKCOWREBBAJ'
-    >>> manager  # doctest: +ELLIPSIS
-    >...x0 ta tcejbo reganaMtxetnoCrotareneG_.biltxetnoc<
-    >>> manager.__exit__(None, None, None)  # <4>
-    >>> monster
-    'JABBERWOCKY'
-
-# end::MIRROR_GEN_DEMO_2[]
-
-The context manager can handle and "swallow" exceptions.
-The following test does not pass under doctest (a
-ZeroDivisionError is reported by doctest) but passes
-if executed by hand in the Python 3 console (the exception
-is handled by the context manager):
-
-# tag::MIRROR_GEN_DEMO_3[]
-
-    >>> from mirror_gen import looking_glass
-    >>> with looking_glass():
-    ...      print('Humpty Dumpty')
-    ...      x = 1/0  # <1>
-    ...      print('END')  # <2>
-    ...
-    ytpmuD ytpmuH
-    Please DO NOT divide by zero!
-
-# end::MIRROR_GEN_DEMO_3[]
-
-    >>> with looking_glass():
-    ...      print('Humpty Dumpty')
-    ...      x = no_such_name  # <1>
-    ...      print('END')  # <2>
-    ...
-    Traceback (most recent call last):
-      ...
-    NameError: name 'no_such_name' is not defined
-
-
-
-"""
-
-
-# tag::MIRROR_GEN_EXC[]
-
-import contextlib
-
-
-@contextlib.contextmanager
-def looking_glass():
-    import sys
-    original_write = sys.stdout.write
-
-    def reverse_write(text):
-        original_write(text[::-1])
-
-    sys.stdout.write = reverse_write
-    msg = ''  # <1>
-    try:
-        yield 'JABBERWOCKY'
-    except ZeroDivisionError:  # <2>
-        msg = 'Please DO NOT divide by zero!'
-    finally:
-        sys.stdout.write = original_write  # <3>
-        if msg:
-            print(msg)  # <4>
-
-
-# end::MIRROR_GEN_EXC[]