PyQuick: String #2

string2.py

# D. verbing
# Given a string, if its length is at least 3,
# add 'ing' to its end.
# Unless it already ends in 'ing', in which case
# add 'ly' instead.
# If the string length is less than 3, leave it unchanged.
# Return the resulting string.
def verbing(s):
  if len(s) < 3:
    return s
  elif s[-3:] == 'ing':
    return s + 'ly'
  else:
    return s + 'ing'


# E. not_bad
# Given a string, find the first appearance of the
# substring 'not' and 'bad'. If the 'bad' follows
# the 'not', replace the whole 'not'...'bad' substring
# with 'good'.
# Return the resulting string.
# So 'This dinner is not that bad!' yields:
# This dinner is good!
def not_bad(s):
  first_found = s.find('not')
  second_found = s.find('bad')
  if first_found == -1 or second_found == -1:
    return s
  else:
    if second_found > first_found:
      return s[:first_found] + 'good' + s[second_found + 3:]
    else:
      return s


# F. front_back
# Consider dividing a string into two halves.
# If the length is even, the front and back halves are the same length.
# If the length is odd, we'll say that the extra char goes in the front half.
# e.g. 'abcde', the front half is 'abc', the back half 'de'.
# Given 2 strings, a and b, return a string of the form
#  a-front + b-front + a-back + b-back
def front_back(a, b):
  
  a_len = len(a)
  a_res = int(a_len / 2)
  if a_len % 2:
    a_res = a_res + 1
  
  a_front = a[:a_res]
  a_back = a[a_res:]
  
  b_len = len(b)
  b_res = int(b_len / 2)
  if b_len % 2:
    b_res = b_res + 1
  
  b_front = b[:b_res]
  b_back = b[b_res:]
  
  return a_front + b_front + a_back + b_back