diff --git a/csst_proto/scratch.py b/csst_proto/scratch.py
new file mode 100644
index 0000000000000000000000000000000000000000..394e31fcfb38f8258810d6964319ec320891e875
--- /dev/null
+++ b/csst_proto/scratch.py
@@ -0,0 +1,33 @@
+import numpy as np
+
+
+def print_some_numbers(start: int, stop=10):
+    """ this function prints some numbers
+
+    Parameters
+    ----------
+    start: int
+        start number
+    stop: int
+        stop number
+
+    Notes
+    -----
+    this algorithm ...
+    """
+    for i in np.arange(start, stop):
+        print(i)
+    return
+
+
+class AClass:
+    def __init__(self):
+        self.a = 1
+
+    def print_a(self):
+        if True:
+            print(self.a)
+
+
+if __name__ == "__main__":
+    print_some_numbers(start=1, stop=5)