Issue #27210: Fix doctests for a few modules.

Initial patch by Jelle Zijlstra.

Doc/library/difflib.rst

@@ -170,8 +170,7 @@ diffs. For comparing directories and files, see also, the :mod:`filecmp` module.
 
       >>> s1 = ['bacon\n', 'eggs\n', 'ham\n', 'guido\n']
       >>> s2 = ['python\n', 'eggy\n', 'hamster\n', 'guido\n']
-      >>> for line in context_diff(s1, s2, fromfile='before.py', tofile='after.py'):
-      ...     sys.stdout.write(line)  # doctest: +NORMALIZE_WHITESPACE
+      >>> sys.stdout.writelines(context_diff(s1, s2, fromfile='before.py', tofile='after.py'))
       *** before.py
       --- after.py
       ***************
@@ -209,7 +208,7 @@ diffs. For comparing directories and files, see also, the :mod:`filecmp` module.
       >>> import keyword
       >>> get_close_matches('wheel', keyword.kwlist)
       ['while']
-      >>> get_close_matches('apple', keyword.kwlist)
+      >>> get_close_matches('pineapple', keyword.kwlist)
       []
       >>> get_close_matches('accept', keyword.kwlist)
       ['except']
@@ -303,8 +302,7 @@ diffs. For comparing directories and files, see also, the :mod:`filecmp` module.
 
       >>> s1 = ['bacon\n', 'eggs\n', 'ham\n', 'guido\n']
       >>> s2 = ['python\n', 'eggy\n', 'hamster\n', 'guido\n']
-      >>> for line in unified_diff(s1, s2, fromfile='before.py', tofile='after.py'):
-      ...     sys.stdout.write(line)   # doctest: +NORMALIZE_WHITESPACE
+      >>> sys.stdout.writelines(unified_diff(s1, s2, fromfile='before.py', tofile='after.py'))
       --- before.py
       +++ after.py
       @@ -1,4 +1,4 @@

Doc/library/ftplib.rst

@@ -57,7 +57,7 @@ The module defines the following items:
     >>> with FTP("ftp1.at.proftpd.org") as ftp:
     ...     ftp.login()
     ...     ftp.dir()
-    ...
+    ... # doctest: +SKIP
     '230 Anonymous login ok, restrictions apply.'
     dr-xr-xr-x   9 ftp      ftp           154 May  6 10:43 .
     dr-xr-xr-x   9 ftp      ftp           154 May  6 10:43 ..

Doc/library/nntplib.rst

@@ -75,7 +75,7 @@ The module itself defines the following classes:
     >>> from nntplib import NNTP
     >>> with NNTP('news.gmane.org') as n:
     ...     n.group('gmane.comp.python.committers')
-    ...
+    ... # doctest: +SKIP
     ('211 1755 1 1755 gmane.comp.python.committers', 1755, 1, 1755, 'gmane.comp.python.committers')
     >>>
 
@@ -261,9 +261,9 @@ tuples or objects that the method normally returns will be empty.
 
       >>> from datetime import date, timedelta
       >>> resp, groups = s.newgroups(date.today() - timedelta(days=3))
-      >>> len(groups)
+      >>> len(groups) # doctest: +SKIP
       85
-      >>> groups[0]
+      >>> groups[0] # doctest: +SKIP
       GroupInfo(group='gmane.network.tor.devel', last='4', first='1', flag='m')
 
 
@@ -312,9 +312,9 @@ tuples or objects that the method normally returns will be empty.
    is a dictionary mapping group names to textual descriptions.
 
       >>> resp, descs = s.descriptions('gmane.comp.python.*')
-      >>> len(descs)
+      >>> len(descs) # doctest: +SKIP
       295
-      >>> descs.popitem()
+      >>> descs.popitem() # doctest: +SKIP
       ('gmane.comp.python.bio.general', 'BioPython discussion list (Moderated)')