Merge pull request #31 from cknd/add_etype_filter

Add option to disable full tracebacks for certain exceptions

Author: cknd

CHANGELOG.md

@@ -0,0 +1,11 @@
+# Upcoming
+
+## Added
+- Option to disable verbose formatting for given types of exceptions (generating a standard python-like traceback instead)
+
+## Changed
+- Disabled verbose formatting for KeyboardInterrupts by default. Call `format(..., suppressed_exceptions=None`) to enforce verbose printing even on a keyboard interrupt.
+
+# 0.2.3 - May 29, 2019
+
+(beginning of time)

demo_keyboard_interrupt.py

@@ -0,0 +1,19 @@
+import time
+import stackprinter
+
+
+def blocking_function(x):
+    print('ctrl-C me')
+    time.sleep(5)
+
+try:
+    some_value = 'spam'
+    blocking_function(some_value)
+except:
+    # Default: Only print summary info
+    stackprinter.show()
+    # Override:
+    # stackprinter.show(suppressed_exceptions=None)
+    # stackprinter.show(suppressed_exceptions=[])
+
+

stackprinter/__init__.py

@@ -117,6 +117,11 @@ def format(thing=None, **kwargs):
         Example: To hide numpy internals from the traceback, set
         `suppressed_paths=[r"lib/python.*/site-packages/numpy"]`
 
+    suppressed_exception_types: list of exception classes
+        Show less verbose formatting for exceptions in this list.
+        By default, this list is `[KeyboardInterrupt]`. Set to `[]`
+        to force verbose formatting even on a keyboard interrupt.
+
     reverse: bool
         List the innermost frame first.
 

stackprinter/formatting.py

@@ -108,18 +108,20 @@ def format_stack_from_frame(fr, add_summary=False, **kwargs):
 
 
 def format_exc_info(etype, evalue, tb, style='plaintext', add_summary='auto',
-                    reverse=False, **kwargs):
+                    reverse=False, suppressed_exceptions=[KeyboardInterrupt],
+                    **kwargs):
     """
     Format an exception traceback, including the exception message
 
-    keyword args like stackprinter.format()
+    see stackprinter.format() for docs about the keyword arguments
     """
     msg = ''
     try:
-        # First, recursively format any chained exceptions (exceptions during whose handling
-        # the given one happened).
-        # TODO: refactor this whole messy function to return a more... structured datastructure
-        # before assembling a string, so that e.g. a summary of the whole chain can be shown at
+        # First, recursively format any chained exceptions (exceptions
+        # during whose handling the given one happened).
+        # TODO: refactor this whole messy function to return a
+        # more... structured datastructure before assembling a string,
+        # so that e.g. a summary of the whole chain can be shown at
         # the end.
         context = getattr(evalue, '__context__', None)
         cause = getattr(evalue, '__cause__', None)
@@ -152,30 +154,38 @@ def format_exc_info(etype, evalue, tb, style='plaintext', add_summary='auto',
                 msg += clr % chain_hint
 
         # Now, actually do some formatting:
-        msgs = []
+        parts = []
         if tb:
             frameinfos = [ex.get_info(tb_) for tb_ in _walk_traceback(tb)]
-            stack_msg = format_stack(frameinfos, style=style, reverse=reverse, **kwargs)
-            msgs.append(stack_msg)
+            if (suppressed_exceptions and
+                issubclass(etype, tuple(suppressed_exceptions))):
+                summary = format_summary(frameinfos, style=style,
+                                         reverse=reverse, **kwargs)
+                parts = [summary]
+            else:
+                whole_stack = format_stack(frameinfos, style=style,
+                                           reverse=reverse, **kwargs)
+                parts.append(whole_stack)
 
-            if add_summary == 'auto':
-                add_summary = stack_msg.count('\n') > 50
+                if add_summary == 'auto':
+                    add_summary = whole_stack.count('\n') > 50
 
-            if add_summary:
-                summ = format_summary(frameinfos, style=style, reverse=reverse, **kwargs)
-                summ += '\n'
-                msgs.append('---- (full traceback below) ----\n\n' if reverse else
-                            '---- (full traceback above) ----\n')
-                msgs.append(summ)
+                if add_summary:
+                    summary = format_summary(frameinfos, style=style,
+                                             reverse=reverse, **kwargs)
+                    summary += '\n'
+                    parts.append('---- (full traceback below) ----\n\n' if reverse else
+                                 '---- (full traceback above) ----\n')
+                    parts.append(summary)
 
         exc = format_exception_message(etype, evalue, style=style)
-        msgs.append('\n\n' if reverse else '')
-        msgs.append(exc)
+        parts.append('\n\n' if reverse else '')
+        parts.append(exc)
 
         if reverse:
-            msgs = reversed(msgs)
+            parts = reversed(parts)
 
-        msg += ''.join(msgs)
+        msg += ''.join(parts)
 
     except Exception as exc:
         import os