1. def f(x): counter = 0 y = 0; while counter <=x: y += x counter += 1 return(y) assertEqual(f(4),______) What does this do? L OOPS :

2. W HILE LOOPS def f(): count = input("Enter a number") total = 0 while count >= 1: total += count count = count -1 return(total) input: asks the user for some form of input – the user should type something in. Whatever the user types in is returned from input. In this case, it is put in the variable count.

3. def ThreeYearOld(): response = "" while response != "Because.": response = input("Why?") print("Oh. Okay.") ThreeYearOld() W HILE L OOP

4. W HILE LOOPS def f(): total = 0 while count >= 1: total += count count = count -1 return(total) What does this calculate?

5. W HILE LOOPS def f(): total = 0 count = 4; while count >= 1: total += count return(total) What does this calculate?

6. RULES : If using an iterator, it must be initialized before we start the loop (outside the loop!) count = 4; while count >= 1:... The loop has to stop. Inside the loop something must change each time so that we hit the stopping condition Like recursion, we must progress toward the stopping condition while count >= 1: total += count count = count -1

7. def f(x): return(x>5) def y(ls): ct = 0 while ((ct < len(ls)) and not(f(ls[ct]))): ct += 1 return(ct) list1 = [3,-1,2,4,8,7,5] assertEqual(y(list1),______)

8. def z(ls): ct = 0 x = 0 while (ct < len(ls)): if ls[ct] > ls[x]: x = ct ct += 1 return(x) list1 = [3,-1,2,4,8,7,5] assertEqual(z(list1),______)

9. def z(ct): x = 0 while (ct >= 0): x += ct ct = ct - 1 return(x) assertEqual(z(5),______) Versus: def z(ct): x = 0 while (ct >= 0): ct = ct - 1 x += ct return(x) assertEqual(z(5),______)

10. def q(ls): ct = 0 while (ct < len(ls)/2): ls[len(ls)-(ct+1)],ls[ct] = ls[ct],ls[len(ls)-(ct + 1)] ct += 1 return(ls) list1 = [3,-1,2,4,8,7,5] assertEqual(q(list1),________________)

11. def q(x,y): ct = 0 while (ct < x): ct2 = 0 while (ct2 < y): print ct + ct2 ct2 += 1 ct += 1 q(4,3)

12. def q(x,y): ct = 0 while (ct < x): ct2 = ct while (ct2 < y): print ct + ct2 ct2 += 1 ct += 1 q(4,3)

13. def q(x): ct = 0 while (ct < x): ct2 = x while (ct2 > ct): print ct + ct2 ct2 -= 1 ct += 1 q(4)

14. F OR LOOPS A for loop gets each successive element in a sequence Examples: for i in range(0,10): print(i) (equivalent to: i = 0 while i < 10: print(i) i = i+1 for i in range(0, 50, 5): print(i) for i in range(10, 0, -1): print(i)

15. L EN, IN def f(lv): x = len(lv) print(x) for y in range(0,x): print(lv[y]) listvar = ["ham","am","boat","goat","there","anywhere"] f(listvar) What does this do?

16. F OR LOOPS def f(word): for x in word: print(x) wvar = " birthday " f(wvar) svar=[ " I ", " do ", " not ", " like ", " green ", " eggs ", " and ", " ham " ] f(svar) What do you think this does?

17. def f(lv): x = len(lv) print(x) for y in range(0,x): if "t" in lv[y]: print(lv[y]) listvar = ["ham","am","boat","goat","there","anywhere"] f(listvar) What does this do?

18. def f(lv): x = len(lv) print(x) for y in range(0,x): for z in range(0,len(lv[y])): print(lv[y][z]) print listvar = ["ham","am","boat","goat","there","anywhere"] f(listvar) What does this do?

19. W HAT DOES THIS DO ? def f(word): newstr = "" for i in range(1,len(word)+1): newstr += word[-i] return(newstr) wvar = "sesquipedalian" print(f(wvar))

20. import random def f(word): high = len(word) low = -len(word) newstr = "" for i in range(10): position = random.randrange(low, high) newstr += word[position] return(newstr) wvar = "sesquipedalian" print(f(wvar)) Tougher: What does this do?

21. W HAT DOES THIS DO ? def f(message): new_message = "" SPECIALLETTERS = "dlmstp" for letter in message: if letter.lower() not in SPECIALLETTERS: new_message += letter return(new_message) mvar = "Hi, my name is Lassie" print("Your message is: now" + f(mvar))

22. S OMETHING YOU CAN ’ T DO : word = “game”; word[0] = “l”; Instead: def f(message): newmessage = "" print("old string: " + message) for x in message: if x == "g": newmessage += "l" else: newmessage += x return(newmessage) mvar = "game" print("new string: " + f(mvar)) mvar = "pogysyggabicaggy" print("new string: " + f(mvar))

23. def SS(ls): for i in range(len(ls)): s=ls[i] si = i for j in range(i, len(ls)): if (ls[j]<s): s=ls[j] si=j ls[si]=ls[i] ls[i]=s return ls a=[3,5,2,7,1] print (a) print ("=>", SS(a))

24. def is(ls): for i in range(0,len(ls)): x = ls[i] j = i-1 while (j >= 0) and (ls[j] > x): ls[j+1] = ls[j] j = j-1 ls[j+1] = x return(ls) ls=[3,1,2,6,4,7] is(ls) print(ls)

25. def bs(list2): i = 0; swap_test = False while ((i < len(list2)-1) and (swap_test == False)): swap_test = True for j in range(0, len(list2) - i - 1): if list2[j] > list2[j + 1]: list2[j], list2[j + 1] = list2[j + 1], list2[j] swap_test = False i += 1 return(list2) ls = [3,2,4,7,1] print(bs(ls))