bpo-27200: Fix doctests in programming.rst and datetime.rst (#401)

Author: marco-buttu

Doc/conf.py

@@ -8,6 +8,7 @@
 
 import sys, os, time
 sys.path.append(os.path.abspath('tools/extensions'))
+sys.path.append(os.path.abspath('includes'))
 
 # General configuration
 # ---------------------

Doc/faq/programming.rst

@@ -1849,7 +1849,7 @@ containing statements like ::
 will continue to work with the old version of the imported objects.  If the
 module contains class definitions, existing class instances will *not* be
 updated to use the new class definition.  This can result in the following
-paradoxical behaviour:
+paradoxical behaviour::
 
    >>> import importlib
    >>> import cls
@@ -1860,7 +1860,7 @@ paradoxical behaviour:
    False
 
 The nature of the problem is made clear if you print out the "identity" of the
-class objects:
+class objects::
 
    >>> hex(id(c.__class__))
    '0x7352a0'

Doc/includes/tzinfo-examples.py renamed to Doc/includes/tzinfo_examples.py

@@ -1221,7 +1221,7 @@ Instance methods:
 
 
       >>> from datetime import datetime
-      >>> datetime.now().isoformat(timespec='minutes')
+      >>> datetime.now().isoformat(timespec='minutes')   # doctest: +SKIP
       '2002-12-25T00:00'
       >>> dt = datetime(2015, 1, 1, 12, 30, 59, 0)
       >>> dt.isoformat(timespec='microseconds')
@@ -1781,9 +1781,11 @@ There is one more :class:`tzinfo` method that a subclass may wish to override:
           else:
               return dt
 
-Example :class:`tzinfo` classes:
+In the following :download:`tzinfo_examples.py
+<../includes/tzinfo_examples.py>` file there are some examples of
+:class:`tzinfo` classes:
 
-.. literalinclude:: ../includes/tzinfo-examples.py
+.. literalinclude:: ../includes/tzinfo_examples.py
 
 Note that there are unavoidable subtleties twice per year in a :class:`tzinfo`
 subclass accounting for both standard and daylight time, at the DST transition
@@ -1804,6 +1806,8 @@ When DST starts (the "start" line), the local wall clock leaps from 1:59 to
 ``astimezone(Eastern)`` won't deliver a result with ``hour == 2`` on the day DST
 begins.  For example, at the Spring forward transition of 2016, we get
 
+    >>> from datetime import datetime, timezone
+    >>> from tzinfo_examples import HOUR, Eastern
     >>> u0 = datetime(2016, 3, 13, 5, tzinfo=timezone.utc)
     >>> for i in range(4):
     ...     u = u0 + i*HOUR