update,

Man1130/jupyter/Man1130-python-comission/course_materials/Note/a1-4-function.py

@@ -0,0 +1,30 @@
+def say_hello():
+    print('Hello World!')
+
+
+def area_of_square(length):
+    return length**2
+
+
+def area_of_circle(radius):
+    pi = 3.1415926
+    return pi*radius**2
+
+# pi can also be defined outside of the function
+# good and bad?
+# what if someone change the value outside?
+
+
+def area_of_rectangle(length,width):
+    return length*width
+
+
+
+def app():
+    age = int(input('What\'s your age?'))
+    print('Your age is {}'.format(age))
+    print('-------')
+    app()
+
+app()
+