diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..60cf25e
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,5 @@
+
+# Python bytecode from the gate scripts and their tests (R-404 added test_golden_notice.py,
+# which imports controller_gates.py and so writes controller/scripts/__pycache__).
+__pycache__/
+*.pyc