1. Week 3 Lab1 Review Dina A. Said dasaid@ucalgary.ca

2. Mathematical operations  Suppose that x= 7, y =2  Z= x + y =9  Z= x-y = 5  Z= x*y = 14  Z= x / y = 3 (because both of them are integers)  Z= 7.0 / 2.0 = 7 / 2.0 = 7.0 / 2 = 3.5  Z= x % y = 1 (the reminder of the division) 3/23/2009CPSC203- Wee3 Lab1

3. Mod operation  The result in the reminder of the division  10%2= 0  11%2 =1  15 % 3 =0  17 % 3 = 2  16 % 3 = 1  To know if y is divisible by x, check if y % x =0  X is even if x % 2=0  X is odd if x% 2 =1 3/23/2009CPSC203- Wee3 Lab1

4. Notes  x =2  z=1  z = z+ x = 3  z+= x = 3  z=z+x is the same as z+=x 3/23/2009CPSC203- Wee3 Lab1

5. Parameters passing  def myFunc(name, ID):  Print name, Id  When u execute myFunc in the black window:  myFunc(“John”, 26378)  def printList(myList):  for i in myList: print i  When you execute printList in the black window:  printList([1,2,3])  printList([7]) 3/23/2009CPSC203- Wee3 Lab1

6. Note  To know the length of a list, use command len(myList)  def printList(myList):  Print “You passed”, len(myList), “ parameters”  for i in myList: print i 3/23/2009CPSC203- Wee3 Lab1

7. If-else condition if test1: statements1 elif test2: statements2 else: statements3 IMP:  Don’t forget : after the condition  For equal test, you must use “== “e.g. if x==y  There is no condition after else 3/11/2009CPSC203- Week2- Lab27

8. Example  Write a function that accepts a number x as a parameter and checks if this number if positive, negative, or zero Think before looking to answer 3/23/2009CPSC203- Wee3 Lab1

9. 3/23/2009CPSC203- Wee3 Lab1 def check(x): if (x>0): print "Positive" elif (x<0): print "Negative" else: print "Zero"

10. For loop for target in object: statements Example: modify the previous program to accept a list of numbers. Do a for loop to check whether each number in the list is positive, negative, or zero Test your program with check([-4,7,0,-1,9]) 3/23/2009CPSC203- Wee3 Lab1

11. 3/23/2009CPSC203- Wee3 Lab1 def check(list): for x in list: if (x>0): print "Positive" elif (x<0): print "Negative" else: print "Zero"

12. Example  Modify the previous program to count the number of even numbers in the list 3/23/2009CPSC203- Wee3 Lab1

13. 3/23/2009CPSC203- Wee3 Lab1 def check(list): count=0 for x in list: if (x>0): count=count+1 print "No. of positive numbers is ", count