diff --git a/src/com/hankcs/algorithm/simple_utils.py b/src/com/hankcs/algorithm/simple_utils.py
new file mode 100644
index 0000000..f7b95d6
--- /dev/null
+++ b/src/com/hankcs/algorithm/simple_utils.py
@@ -0,0 +1,19 @@
+def reverse_string(text):
+    """Reverses the characters in a string."""
+    return text[::-1]
+
+def count_words(sentence):
+    return len(sentence.split())
+
+def celsius_to_fahrenheit(celsius):
+    return (celsius * 9/5) + 32
+
+def fibonacci(n):
+    if not isinstance(n, int):
+        raise TypeError("n must be a non-negative integer")
+    if n < 0:
+        raise ValueError("n must be non-negative")
+    a, b = 0, 1
+    for _ in range(n):
+        a, b = b, a + b
+    return a
diff --git a/src/com/hankcs/algorithm/test.py b/src/com/hankcs/algorithm/test.py
new file mode 100644
index 0000000..6b835ef
--- /dev/null
+++ b/src/com/hankcs/algorithm/test.py
@@ -0,0 +1,7 @@
+
+def reverse_string(text):
+    return text[::-1]
+
+
+if __name__ == "__main__":
+    print(reverse_string("hello"))
\ No newline at end of file