More 2D lists (class slides)

CSC 110 – 2D lists Manipulation

Announcements

• Pay attention do dates
  • Final exam: Dec 13, Friday – 6:00pm - 8:00pm in S SCI 100
  • Projects 11 and 12 due on WEDNESDAY, Dec 11

Write functions side-by-side

Write a function called remove_first that takes in a list of lists (2D list) and removes the first element of each sublist.

Write a function called remove_odds that takes in a list of list (2D list) of numbers and removes all values that are odd.

Name your file removing.py and submit it to gradescope for attendance

Solutions

def remove_first(list_of_lists):
  for sublist in list_of_lists:
    if len(sublist) > 0:
      sublist.pop(0)
  return list_of_lists

def remove_odds(list_of_lists):
  for sublist in list_of_lists:
    for i in range(len(sublist)-1, -1, -1):
      if sublist[i] % 2 == 1:
        sublist.pop(i)
  return list_of_lists

if __name__ == "__main__":
  original_list = [["banana", "apple"], [], ["pear"]]
  remove_first(original_list)
  assert original_list == [["apple"], [], []]
  
  numbers = [[1, 1, 1], [0, 0], []]
  remove_odds(numbers)
  assert numbers == [[], [0, 0], []]

Write functions side-by-side

Write a function called censor_consonants that takes as argument a string and returns the string with the consonants replaced with "*".

Write a function called replace_consonants that takes as argument a list of characters (strings of length one) and replaces the consonants with a "*".

Solutions

def censor_consonants(string):
  new_string = ""
  for char in string:
    if char not in "aeiou":
      new_string += "*"
    else:
      new_string += char
  return new_string

def replace_consonants(strings):
  for i in range(len(strings)):
    if strings[i] not in "aeiou":
      strings[i] = "*"
  return strings

if __name__ == "__main__":
  assert censor_consonants("abcd") == "a***"
  
  letters = ["a", "b", "c", "d"]
  replace_consonants(letters)
  assert letters == ["a", "*", "*", "*"]