- Write a function called getLetter() that asks the user for a letter
and returns the given letter. Your function should check to make sure the user
enters just a single letter. If the user enters anything other than a single
letter, the function should ask again, until it receives valid input.
- Write a function called avgList that takes a list of
numbers as input and returns their average. For example,
avgList([5, 10, 5, 4]) should return 6. Write a
main program to test the function.
- Write a function called maxList that takes a list of
numbers as input and returns the largest number in the list. For
example, maxList([7,4,8,1]) should return 8. Write
a main program to test the function.
- Consider the following program.
def main():
print "in main"
test = "whee"
check = "e"
answer = helper(test, check)
print "the answer is", answer
def helper(word, letter):
print "in helper"
print "word:", word
print "letter:", letter
x = 0
for ch in word:
if ch == letter:
x = x+1
# draw stack here
return x
main()
- Draw the call stack as it would look just prior to returning from
helper.
- What is the program's output (i.e. what is printed when the program is run)?
- What does the helper function compute?
- What would helper("moobaalalala", "a") return?
- What would helper("zoo", "a") return?
- Trace through the following code, show the output from its entire
execution, and draw the stack as it would look before the return statement in
function foo:
def main(): OUTPUT STACK
print "in main"
b = foo(5)
print len(b)
print b[0]
print b[1][1]
def foo(n):
print "in foo"
biglist = []
for i in range (n):
sublist = ["h", i, i+10]
biglist.append(sublist)
# draw stack here
return biglist
main()
What is the type and value of each of the following expressions:
value type
(1) biglist
(2) biglist[2]
(3) biglist[2][0]
(4) biglist[1][2]
(5) len(biglist)
(6) len(biglist[1])
- Write a program that reads in the lines from a file called infile.txt
and creates an acronym from the first letter of each line.
For example, if the input file is:
Thanks
Goodness
It's
Friday
Your program will create and print out the string "TGIF"