--- a
+++ b/test_environment.py
@@ -0,0 +1,25 @@
+import sys
+
+REQUIRED_PYTHON = "python3"
+
+
+def main():
+    system_major = sys.version_info.major
+    if REQUIRED_PYTHON == "python":
+        required_major = 2
+    elif REQUIRED_PYTHON == "python3":
+        required_major = 3
+    else:
+        raise ValueError("Unrecognized python interpreter: {}".format(
+            REQUIRED_PYTHON))
+
+    if system_major != required_major:
+        raise TypeError(
+            "This project requires Python {}. Found: Python {}".format(
+                required_major, sys.version))
+    else:
+        print(">>> Development environment passes all tests!")
+
+
+if __name__ == '__main__':
+    main()