Python Exercise Help

[Halldk]

Hey, i am trying out the python course you guys have here on google, and i have run into a little problem with the examples i've downloaded, i get the answer they want me to, like they want the number of donuts to say "Number of donuts: 4" i get this exact answer, but it still has an x for the prefix, which says im wrong. here is the code that i used

********************************************************************CODE****************************************************************************

#!/usr/bin/python -tt

# Copyright 2010 Google Inc.

# Licensed under the Apache License, Version 2.0

# http://www.apache.org/licenses/LICENSE-2.0

# Google's Python Class

# http://code.google.com/edu/languages/google-python-class/

# Basic string exercises

# Fill in the code for the functions below. main() is already set up

# to call the functions with a few different inputs,

# printing 'OK' when each function is correct.

# The starter code for each function includes a 'return'

# which is just a placeholder for your code.

# It's ok if you do not complete all the functions, and there

# are some additional functions to try in string2.py.

# A. donuts

# Given an int count of a number of donuts, return a string

# of the form 'Number of donuts: <count>', where <count> is the number

# passed in. However, if the count is 10 or more, then use the word 'many'

# instead of the actual count.

# So donuts(5) returns 'Number of donuts: 5'

# and donuts(23) returns 'Number of donuts: many'

def donuts(count):

  # +++your code here+++

  if count >= 10:

    print 'Number of donuts: many'

  else:

    print 'Number of donuts:', count

  return

# B. both_ends

# Given a string s, return a string made of the first 2

# and the last 2 chars of the original string,

# so 'spring' yields 'spng'. However, if the string length

# is less than 2, return instead the empty string.

def both_ends(s):

  # +++your code here+++

  if len(s) <=2:

    print 

  else:

    print s[0:2] + s[-2:]

  return

# C. fix_start

# Given a string s, return a string

# where all occurences of its first char have

# been changed to '*', except do not change

# the first char itself.

# e.g. 'babble' yields 'ba**le'

# Assume that the string is length 1 or more.

# Hint: s.replace(stra, strb) returns a version of string s

# where all instances of stra have been replaced by strb.

def fix_start(s):

  # +++your code here+++

  stra = s[0]

  s.find(stra)

  strb = "*"

  strc = s[1:]

  strc.replace(stra, strb)

  strd = s[0] + strc.replace(stra, strb)

  print strd

  return

# D. MixUp

# Given strings a and b, return a single string with a and b separated

# by a space '<a> <b>', except swap the first 2 chars of each string.

# e.g.

#   'mix', pod' -> 'pox mid'

#   'dog', 'dinner' -> 'dig donner'

# Assume a and b are length 2 or more.

def mix_up(a, b):

  # +++your code here+++

  stra = a[0:2]

  strb = b[0:2]

  strc = a.replace(stra, strb)+", " +b.replace(strb, stra)

  print strc

  return

# Provided simple test() function used in main() to print

# what each function returns vs. what it's supposed to return.

def test(got, expected):

  if got == expected:

    prefix = ' OK '

  else:

    prefix = '  X '

  print '%s got: %s expected: %s' % (prefix, repr(got), repr(expected))

# Standard boilerplate to call the main() function.

# Provided main() calls the above functions with interesting inputs,

# using test() to check if each result is correct or not.

def main():

  print 'donuts'

  # Each line calls donuts, compares its result to the expected for that call.

  test(donuts(4), 'Number of donuts: 4')

  test(donuts(9), 'Number of donuts: 9')

  test(donuts(10), 'Number of donuts: many')

  test(donuts(99), 'Number of donuts: many')

  print

  print 'both_ends'

  test(both_ends('spring'), 'spng')

  test(both_ends('Hello'), 'Helo')

  test(both_ends('a'), '')

  test(both_ends('xyz'), 'xyyz')

  

  print

  print 'fix_start'

  test(fix_start('babble'), 'ba**le')

  test(fix_start('aardvark'), 'a*rdv*rk')

  test(fix_start('google'), 'goo*le')

  test(fix_start('donut'), 'donut')

  print

  print 'mix_up'

  test(mix_up('mix', 'pod'), 'pox mid')

  test(mix_up('dog', 'dinner'), 'dig donner')

  test(mix_up('gnash', 'sport'), 'spash gnort')

  test(mix_up('pezzy', 'firm'), 'fizzy perm')

if __name__ == '__main__':

  main()

************************************************************************************END CODE***********************************************************************

with out all of the astrides of course, and when i run this i get something like this (because i cant copy it from my command prompt, and frankly, im too lazy to type it all)

string1.py

donuts

Number of donuts: 4

    X  got: None expected: 'Number of donuts: 4'

Number of donuts: 9

    X got: None expected:  'Number of donuts: 9'

and so on and so forth, 

both_ends

spng

    X  got: None expected: 'spng'

Helo

    X  got: None expected: 'Helo'

and so on and so forth, same with all the others. I know this should not bother me, seeing as how i know i have the right answer, but, i want to know why it isnt giving me credit for it (I know this seems stupid, but im 16, everything i do is stupid)

Any idea whats wrong? 

[Robert Mandić]

User RETURN instead of PRINT in your function.

--
Lp, Robert

[Hubert campbell]

ugh... did I miss the Return function in the video lecture? It's not in the notes.

[Dustin Hall]

I dont think they specify, but instead of using print, you use return, and it sends it to the command line interface, so it can be checked