add a handy supertrace script

common/lib/supertrace.py

@@ -0,0 +1,52 @@
+"""
+A handy util to print a django-debug-screen-like stack trace with
+values of local variables.
+"""
+
+import sys, traceback
+from django.utils.encoding import smart_unicode
+
+
+def supertrace(max_len=160):
+    """
+    Print the usual traceback information, followed by a listing of all the
+    local variables in each frame.  Should be called from an exception handler.
+
+    if max_len is not None, will print up to max_len chars for each local variable.
+
+    (cite: modified from somewhere on stackoverflow)
+    """
+    tb = sys.exc_info()[2]
+    while True:
+        if not tb.tb_next:
+            break
+        tb = tb.tb_next
+    stack = []
+    frame = tb.tb_frame
+    while frame:
+        stack.append(f)
+        frame = frame.f_back
+    stack.reverse()
+    # First print the regular traceback
+    traceback.print_exc()
+
+    print "Locals by frame, innermost last"
+    for frame in stack:
+        print
+        print "Frame %s in %s at line %s" % (frame.f_code.co_name,
+                                             frame.f_code.co_filename,
+                                             frame.f_lineno)
+        for key, value in frame.f_locals.items():
+            print ("\t%20s = " % smart_unicode(key, errors='ignore')),
+            # We have to be careful not to cause a new error in our error
+            # printer! Calling str() on an unknown object could cause an
+            # error.
+            try:
+                s = smart_unicode(value, errors='ignore')
+                if max_len is not None:
+                    s = s[:max_len]
+                print s
+            except:
+                print "<ERROR WHILE PRINTING VALUE>"
+
+