Problem 1, isSquareFree

def isSquareFree(num):

  for div in range(2,num):
      sq = div*div
      if num % sq == 0: return False
  return True

Problem 1, isPerfect

def isPerfect(num):
    sum = 0
    for div in range(1,num):
        if num % div == 0:
            sum += div
    return sum == num

alternatively, replace the last line/return statement with

    if sum == num:
        return True
    return False

----
We hadn't really covered list comprehensions at the time of the
redux/booster question. If we had this would work

  def isPerfect(num):
      return sum([div for div in range(1,num) if num % div == 0]) == num


---
Problem 1B

def wordCount(words,sub):
   s = 0
   for w in words:
       if sub in words:
           s += 1
   return s

def wordCount(words,sub):
    return len([w for w in words if w.find(sub) > -1])


----
Problem 2

def getAgeList(filename, low, high):
    file = open(filename)

    # The call to strip() on the next line removes the newline character at the
    # end of each line of the file.
    contents = [line.strip().split(",") for line in file]

    # At this point, contents is a list of lists of strings: each element
    # corresponds to an animal, and it contains a list of [name, gestation,
    # life], all of which are strings.

    # Remember to close your files when you're done reading from them!
    file.close()

    # Remember to convert the life expectancy from a string to an int!
    animals = [entry[0] for entry in contents 
               if (low <= int(entry[2])) and (int(entry[2]) <= high)]
    return animals