From 8b789ce21eb8a2c3bc3fe3f80d7a05ec0b653d5c 2012-01-12 21:43:28
From: Thomas Kluyver <takowl@gmail.com>
Date: 2012-01-12 21:43:28
Subject: [PATCH] Find .py files for verbose tracebacks, rather than trying to tokenize .pyc files.

---

diff --git a/IPython/core/ultratb.py b/IPython/core/ultratb.py
index f06a172..2fbe859 100644
--- a/IPython/core/ultratb.py
+++ b/IPython/core/ultratb.py
@@ -100,6 +100,7 @@ from IPython.core.excolors import exception_colors
 from IPython.utils import PyColorize
 from IPython.utils import io
 from IPython.utils import py3compat
+from IPython.utils import pyfile
 from IPython.utils.data import uniq_stable
 from IPython.utils.warn import info, error
 
@@ -873,6 +874,8 @@ class VerboseTB(TBTools):
             tokeneater.name_cont = False
 
             def linereader(file=file, lnum=[lnum], getline=linecache.getline):
+                if file.endswith(('.pyc','.pyo')):
+                    file = pyfile.source_from_cache(file)
                 line = getline(file, lnum[0])
                 lnum[0] += 1
                 return line
diff --git a/IPython/utils/pyfile.py b/IPython/utils/pyfile.py
new file mode 100644
index 0000000..bedecd6
--- /dev/null
+++ b/IPython/utils/pyfile.py
@@ -0,0 +1,23 @@
+"""Utilities for working with Python source files.
+
+Exposes various functions from recent Python standard libraries, along with
+equivalents for older Python versions.
+"""
+import os.path
+
+try:    # Python 3.2
+    from imp import source_from_cache, cache_from_source
+except ImportError:
+    # Python <= 3.1: .pyc files go next to .py
+    def source_from_cache(path):
+        basename, ext = os.path.splitext(path)
+        if ext not in {'.pyc', '.pyo'}:
+            raise ValueError('Not a cached Python file extension', ext)
+        # Should we look for .pyw files?
+        return basename + '.py'
+    
+    def cache_from_source(path, debug_override=None):
+        if debug_override is None:
+            debug_override = __debug__
+        basename, ext = os.path.splitext(path)
+        return basename + '.pyc' if debug_override else '.pyo'