The University of Texas – Pan American CSCI/CMPE 4341 Topic: Programming in Python Chapter 4: Control Structures (Part 2) – Exercises Xiang Lian The University of Texas – Pan American Edinburg, TX 78539 lianx@utpa.edu This set of slides is revised from lecture slides of Prof. John Abraham. -- Xiang Lian

Objectives In this chapter, you will do some exercises about: basic control structures in Python

Multiple Choices Typically, ______ statements are used for counter-controlled repetition. A. for B. while C. repetition D. until Typically, ______ statements are used for sentinel-controlled repetition. The _________statement, when executed in a repetition statement, skips the remaining statements in the loop body and proceeds with the next iteration of the loop. A. break B. exit C. continue D. return The _____operator can be used to ensure that two conditions are both true before choosing a certain path of execution A. and B. && C. or D. || An infinite loop occurs when the loop-continuation condition in a while statement______. A. never becomes true B. never becomes false C. is false D. is true for finite times

Multiple Choices (cont'd) What is the range of function call range(1, 10)? A. [0, 10] B. [0, 10) C. [1, 10] D. [1, 10) What is the value of the expression of 4/5*2+2**(1+2)? A. 8 B. 10 C. 9.6 D. 8.4 What is the value of 5/4, 5//4, and 5%4? A. 1, 1.25, 1 B. 1.25, 1, 4 C. 1, 1, 1 D. 1.25, 1, 1 Which of the following is the appropriate for statement for varying the control variable over the following sequence of values: 5, 10, 15, 20, 25? A. for i in range(25): B. for i in range (5, 25): C. for i in range(5, 25, 5): D. for i in range(25, 5, -5):

True/False Statements The exponentiation operator ** associates left to right. Function call range (4, 7) returns the sequence 4 to 7, inclusive. Sentinel-controlled repetition uses a counter variable to control the number of times a set of instructions executes. String format specifier "%5d" outputs integer with right alignment by default. The expression ((x>y) and (a<b)) is True if either (x>y) is True or (a<b) is True. An expression containing the or operator is True if either or both of its operands are True. The and operator has a higher precedence than the or operator.

What Does the Code Do? for i in range(1, 11): for j in range (1, 11): print ('@', end = ""); print ("");

Debug Errors counter=1 For i in range (1, 10) counter++

Write a Program Use nested for statement to write a Python program to display the triangle of asterisks. Use the following statements: print ("*", end="") # displays asterisks one at a time print ("") # the cursor goes to a new line print (" ", end="") # inserts a space * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

Write a Program (cont'd) Use nested for statement to write a program to display a rectangle. Use the following statements: print ("+", end="") print ("-", end="") print ("|", end="") print ("") print (" ", end="") + - - - - - - - - - - + | |