improve bin

Author: fey

README.md

@@ -22,6 +22,13 @@ This project was built using these tools:
 make install
 ```
 
+### Examples
+
+```bash
+uv run hexlet-python-package 5
+
+2.5
+```
 
 ### Run tests
 

hexlet_python_package/scripts/main.py

@@ -4,7 +4,17 @@
 
 
 def main():
-    print(half(float(sys.argv[-1])))
+    if len(sys.argv) < 2:
+        print("Error: You must provide a number as an argument.")
+        return
+
+    possible_number = sys.argv[1]
+
+    try:
+        number = float(possible_number)
+        print(half(number))
+    except ValueError:
+        print(f"Error: '{possible_number}' is not a valid number.")
 
 
 if __name__ == "__main__":