diff --git a/fizzbuzz.py b/fizzbuzz.py
new file mode 100644
index 0000000..2e380f9
--- /dev/null
+++ b/fizzbuzz.py
@@ -0,0 +1,15 @@
+# @File  : fizzbuzz.py
+# @Author: Wenyuan Gu
+# @Date  : 2020/1/15
+
+
+def fizzbuzz(n):
+    return 'Fizz'[n % 3 * 4:] + 'Buzz'[n % 5 * 4:] or n
+
+
+def main():
+    for i in range(1, 101):
+        print(fizzbuzz(i))
+
+if __name__ == '__main__':
+    main()
\ No newline at end of file
diff --git a/fizzbuzz_test.py b/fizzbuzz_test.py
new file mode 100644
index 0000000..132e38b
--- /dev/null
+++ b/fizzbuzz_test.py
@@ -0,0 +1,20 @@
+# @File  : fizzbuzz_test.py
+# @Author: Wenyuan Gu
+# @Date  : 2020/1/15
+
+
+import pytest
+from fizzbuzz import fizzbuzz
+
+class Test_fizzbuzz():
+    def test2(self):
+        assert fizzbuzz(2) == 2
+    def test3(self):
+        assert fizzbuzz(3) == 'Fizz'
+    def test5(self):
+        assert fizzbuzz(5) == 'Buzz'
+    def test15(self):
+        assert fizzbuzz(15) == 'FizzBuzz'
+
+if __name__ == "__main__":
+    pytest.main()
diff --git a/helloworld.py b/helloworld.py
deleted file mode 100644
index 449b948..0000000
--- a/helloworld.py
+++ /dev/null
@@ -1,2 +0,0 @@
-def get_greetings():
-    return 'Hello World!'
diff --git a/helloworld_test.py b/helloworld_test.py
deleted file mode 100644
index 4c27dfe..0000000
--- a/helloworld_test.py
+++ /dev/null
@@ -1,5 +0,0 @@
-from helloworld import get_greetings
-
-
-def test_get_helloworld():
-    assert get_greetings() == 'Hello World!'