init.py: add an example of using cgitb.enable

[dotfiles.git] / lib / python / init.py

diff --git a/lib/python/init.py b/lib/python/init.py
index 69b9ac162c3411e0feb341c9312ca3f8dba28dcd..1690a42ab9d2996a9fe35e3a681ea62942a53e91 100644 (file)
--- a/lib/python/init.py
+++ b/lib/python/init.py
@@ -114,16 +114,28 @@ def init():
     else:
         try:
             locale.setlocale(locale.LC_ALL, '')
-
         except (ImportError, locale.Error):
             pass  # no locale support or unsupported locale
 
-    # set displayhook
+    # set displayhook and excepthook
 
     from pprint import pprint
+    pager = os.environ.get("PAGER") or 'more'
+
+    # if your pager is 'less', options '-F' and '-R' must be passed to it,
+    # and option '-X' is very much recommended
+    if pager == 'less':
+        less = os.environ.get("LESS") or ''
+        for opt in 'X', 'R', 'F':
+            if opt not in less:
+                less = opt + less
+        os.environ["LESS"] = less
 
-    class BasePPrintPager:
-        def pipe(self, value):
+    class BasePager:
+        def write(self, value):
+            self.stdin.write(value)
+
+        def pprint(self, value):
             pprint(value, stream=self.stdin)
 
         def close(self):
@@ -132,38 +144,48 @@ def init():
     try:
         from subprocess import Popen, PIPE
     except ImportError:
-        class PPrintPager(BasePPrintPager):
+        class Pager(BasePager):
             def __init__(self):
                 self.pipe = Popen(pager, shell=True, stdin=PIPE)
                 self.stdin = self.pipe.stdin
 
             def close(self):
-                BasePPrintPager.close(self)
+                BasePager.close(self)
                 self.pipe.wait()
     else:
-        class PPrintPager(BasePPrintPager):
+        class Pager(BasePager):
             def __init__(self):
                 self.stdin = os.popen(pager, 'w')
-    pager = os.environ.get("PAGER") or 'more'
 
     def displayhook(value):
         if value is not None:
             __builtin__._ = value
-        pprint_pager = PPrintPager()
-        pprint_pager.pipe(value)
-        pprint_pager.close()
+        pager = Pager()
+        pager.pprint(value)
+        pager.close()
 
     sys.displayhook = displayhook
 
-    from traceback import print_exception
+    from traceback import format_exception
 
     def excepthook(etype, evalue, etraceback):
-        pprint_pager = PPrintPager()
-        print_exception(etype, evalue, etraceback, file=pprint_pager.stdin)
-        pprint_pager.close()
+        lines = format_exception(etype, evalue, etraceback)
+        pager = Pager()
+        for line in lines:
+            pager.write(
+                '\033[31m' + line.rstrip('\n') + '\033[0m\n')  # red, reset
+        pager.close()
 
     sys.excepthook = excepthook
 
+    #try:
+    #    import cgitb
+    #except ImportError:
+    #    pass
+    #else:
+    #    # cgitb.enable() overrides sys.excepthook
+    #    cgitb.enable(format='text')
+
     # From Thomas Heller:
     # https://mail.python.org/pipermail/python-list/2001-April/099020.html