Page 214 - Computer Science V2.0 Class 11

04 Input Parameters: None
05 Return value: None
06 '''
07 print(" * ")
08 print(" *** ")
09 print(" ***** ")
10 print(" ******* ")
11
12 def rhombus():
13 '''
14 Objective: To print the rhombus
15 Input Parameters: None
16 Return value: None
17 '''
18 print(" * ")
19 print(" *** ")
20 print(" ***** ")
21 print(" ******* ")
22 print(" ***** ")
23 print(" *** ")
24 print(" * ")
When Program 8.2a is executed, the IDLE responds with no output.

Why does the program not print a triangle and a rhombus?

8.2.1 Calling a Function

Now, we understand that a function definition only provides us a with provision to do something in a program. It
comes into action (i.e. gets executed) only when it is invoked. Invoking a function is also called a function call. So, just
defining a function in a program does not achieve any result unless it is invoked.

A function is executed only when it is invoked. Defining a function ONLY makes a provision to do something.

Next, we use the above definitions of the functions triangle() and rhombus() in Program 8.2b. The program
performs the following tasks:

1. Calls a user-defined function triangle(), to print a triangle.
2. Leaves a blank line of output.
3. Calls user-defined function rhombus() to print a rhombus.
4. Leaves a blank line of output.

5. Calls user-defined function triangle()to print a triangle.

Program 8.2b: Program to display the triangle followed by a rhombus using functions (pattern2.py)
01 def triangle():
02 '''
03 Objective: To print the triangle
04 Input Parameters: None
05 Return value: None
06 '''

200 Touchpad Computer Science (Ver. 2.0)-XI