gh-120254: Add a `commands` argument to `pdb.set_trace` (#120255)

1 files changed, 9 insertions, 4 deletions

diff --git a/Lib/pdb.py b/Lib/pdb.py
index 228de48..dd21207 100644
--- a/Lib/pdb.py
+++ b/Lib/pdb.py
@@ -361,10 +361,14 @@ class Pdb(bdb.Bdb, cmd.Cmd):
         self._chained_exceptions = tuple()
         self._chained_exception_index = 0
 
-    def set_trace(self, frame=None):
+    def set_trace(self, frame=None, *, commands=None):
         Pdb._last_pdb_instance = self
         if frame is None:
             frame = sys._getframe().f_back
+
+        if commands is not None:
+            self.rcLines.extend(commands)
+
         super().set_trace(frame)
 
     def sigint_handler(self, signum, frame):
@@ -2350,13 +2354,14 @@ def runcall(*args, **kwds):
     """
     return Pdb().runcall(*args, **kwds)
 
-def set_trace(*, header=None):
+def set_trace(*, header=None, commands=None):
     """Enter the debugger at the calling stack frame.
 
     This is useful to hard-code a breakpoint at a given point in a
     program, even if the code is not otherwise being debugged (e.g. when
     an assertion fails). If given, *header* is printed to the console
-    just before debugging begins.
+    just before debugging begins. *commands* is an optional list of
+    pdb commands to run when the debugger starts.
     """
     if Pdb._last_pdb_instance is not None:
         pdb = Pdb._last_pdb_instance
@@ -2364,7 +2369,7 @@ def set_trace(*, header=None):
         pdb = Pdb()
     if header is not None:
         pdb.message(header)
-    pdb.set_trace(sys._getframe().f_back)
+    pdb.set_trace(sys._getframe().f_back, commands=commands)
 
 # Post-Mortem interface