add help command

fifth/fifth.py

@@ -7,6 +7,7 @@ class FifthStack:
     def __init__(self):
         self.stack: list[int] = []
         self.commands: dict[str, Callable] = {
+            "help": self.help,
             "push": self.push,
             "pop": self.pop,
             "swap": self.swap,
@@ -38,6 +39,10 @@ class FifthStack:
             print(f"ERROR: division by zero")
             self.stack.extend([a, b])
 
+    def help(self):
+        print("Available commands:", ", ".join(cmd.upper() for cmd in self.commands.keys()))
+        print("Available operations:", ", ".join(self.binary_ops.keys()))
+
     def push(self, value):
         try:
             self.stack.append(int(value))
@@ -80,6 +85,7 @@ class FifthStack:
 
 def main():
     fifth = FifthStack()
+    fifth.help()
 
     while True:
         print(f"stack is {fifth.stack}")

fifth/test_fifth.py

@@ -147,7 +147,14 @@ def test_execute_dup_command():
     assert stack.stack == [7, 7]
 
 
-# Test edge cases
+# Help and edge cases
+def test_help(capsys):
+    stack = FifthStack()
+    stack.help()
+    captured = capsys.readouterr()
+    assert "Available commands:" in captured.out
+    assert "Available operations:" in captured.out
+
 def test_execute_empty_command():
     stack = FifthStack()
     stack.execute("")  # Should do nothing