Make this lab program more useful for examining how trace functions work.

3 files changed, 32 insertions, 62 deletions

diff --git a/lab/run_trace.py b/lab/run_trace.py
new file mode 100644
index 0000000..3822a80
--- /dev/null
+++ b/lab/run_trace.py
@@ -0,0 +1,32 @@
+"""Run a simple trace function on a file of Python code."""
+
+import os, sys
+
+nest = 0
+
+def trace(frame, event, arg):
+    global nest
+
+    if nest is None:
+        # This can happen when Python is shutting down.
+        return None
+
+    print "%s%s %s %d @%d" % (
+        "    " * nest,
+        event,
+        os.path.basename(frame.f_code.co_filename),
+        frame.f_lineno,
+        frame.f_lasti,
+        )
+
+    if event == 'call':
+        nest += 1
+    if event == 'return':
+        nest -= 1
+
+    return trace
+
+the_program = sys.argv[1]
+
+sys.settrace(trace)
+execfile(the_program)
diff --git a/lab/sample.py b/lab/sample.py
deleted file mode 100644
index bb62848..0000000
--- a/lab/sample.py
+++ /dev/null
@@ -1,5 +0,0 @@
-a, b = 1, 0
-if a or b or fn():
-    # Hey
-    a = 3
-d = 4
diff --git a/lab/trace_sample.py b/lab/trace_sample.py
deleted file mode 100644
index 3f81919..0000000
--- a/lab/trace_sample.py
+++ /dev/null
@@ -1,57 +0,0 @@
-import os, sys
-
-global nest
-nest = 0
-
-def trace(frame, event, arg):
-    #if event == 'line':
-    global nest
-
-    print "%s%s %s %d" % (
-        "   " * nest,
-        event,
-        os.path.basename(frame.f_code.co_filename),
-        frame.f_lineno,
-        )
-
-    if event == 'call':
-        nest += 1
-    if event == 'return':
-        nest -= 1
-
-    return trace
-
-def trace2(frame, event, arg):
-    #if event == 'line':
-    global nest
-
-    print "2: %s%s %s %d" % (
-        "   " * nest,
-        event,
-        os.path.basename(frame.f_code.co_filename),
-        frame.f_lineno,
-        )
-
-    if event == 'call':
-        nest += 1
-    if event == 'return':
-        nest -= 1
-
-    return trace2
-
-sys.settrace(trace)
-
-def bar():
-    print "nar"
-
-a = 26
-def foo(n):
-    a = 28
-    sys.settrace(sys.gettrace())
-    bar()
-    a = 30
-    return 2*n
-
-print foo(a)
-#import sample
-#import littleclass