def f(x):

counter = 0

y = 0;

while counter <=x:

y += x

counter += 1

return(y)

assertEqual(f(4),______)

What does this do?

LOOPS:

WHILE LOOPS

def f():count = input("Enter a number") total = 0while count >= 1: total += count count = count -1return(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.

def ThreeYearOld():

response = ""

while response != "Because.":

response = input("Why?")

print("Oh. Okay.")

ThreeYearOld()

WHILE LOOP

WHILE LOOPS

def f():total = 0while count >= 1: total += count count = count -1return(total)

What does this calculate?

WHILE LOOPS

def f():total = 0count = 4;while count >= 1: total += countreturn(total)

What does this calculate?

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 conditionwhile count >= 1: total += count

count = count -1

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),______)

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),______)

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),______)

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),________________)

def q(x,y):

ct = 0

while (ct < x):

ct2 = 0

while (ct2 < y):

print ct + ct2

ct2 += 1

ct += 1

q(4,3)

def q(x,y):

ct = 0

while (ct < x):

ct2 = ct

while (ct2 < y):

print ct + ct2

ct2 += 1

ct += 1

q(4,3)

def q(x):

ct = 0

while (ct < x):

ct2 = x

while (ct2 > ct):

print ct + ct2

ct2 -= 1

ct += 1

q(4)

FOR LOOPS

A for loop gets each successive element in a sequence Examples:for i in range(0,10): print(i)(equivalent to:i = 0while 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)

LEN, 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?

FOR 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?

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?

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?

WHAT 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))

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?

WHAT 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))

SOMETHING 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))

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))

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)

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))