final exam review (slides)

CSC – Final exam review

Announcements

Final exam

• 1pm: Monday May 12, 1:00 - 3:00pm, GITT 129B

• 2pm: Friday May 09, 1:00 - 3:00pm, GITT 129B

• Bring your photo ID

Review of strings

string methods

• string is not mutable, means every string method will return a new string

• indexing a string

("Jimmy42"[0], "Jimmy42"[-1])

('J', '2')

• slicing a string

("Jimmy42"[:2], "Jimmy42"[1:3])

('Ji', 'im')

string methods

• .isnumeric() returns True if all the chars are numeric (0-9)

("Jimmy42".isnumeric(), "42".isnumeric())

(False, True)

• .lower() returns a string with all lowercase chars

• .strip() removing chars in the beginning or end

"Jimmy42".strip('42')

'Jimmy'

• .split() return a list by splitting strings by char

"Jimmy42Jimmy42Jimmy".split('42')

['Jimmy', 'Jimmy', 'Jimmy']

string: concatenation

• age_milestones

• four_letter_anagram

• remove_vowels_string

• every_two_together

• write_word_count

• concatenate

• censor_consonants

string: iteration

• is_numeric

• count_vowels

• vowels_only

• remove_vowels_string

• indices_of_vowels

• count_chars

• censor_consonants

Review of lists

list methods

• list[index] = value mutate a list value using index

• .append(value) append an item to the end of a list

• .insert(index, value) insert a value at index

• .pop(index) remove an item at index

• .remove(value) remove a value

• .extend(list_b) concatenate with another list

• list[index_a:index_b] list slicing

• 2D lists

list: iterate with mutation

• double

• make_even

• make_all_even

• max_list

• total_mean

• remove_names

• remove_odds

• replace_consonants

list: iterate without mutation

• max_list

• sum_all

• every_two_together

• every_two

• count_words

• descr_stats

• flatten

• get_highest_average

Review of dictionaries

dictionary methods

• dict[key] = value mutate a value using key

• dict[key] = value add a new key-value pair

• dict.pop(key) remove a key-value pair using key

• for k in dict: iterate only the keys

• for v in dict.values(): iterate only the values

• for k, v in dict.items(): iterate both

mutating a dictionary

• count_vowels

• sales_tax

• remove_records

• repetition

adding to a dictionary

• count_chars

• count_words

• count_names

• create_dictionary

iterating a dictionary

• merge_dictionaries

• sum_and_multiplication

• get_names

• repetition

• sales_tax

Final exam also includes reading, aggregating or writing to files, and sortings

More practice problems

write a function

Write a python function that does the following:

1. Its name is create_list

2. It takes two arguments, a set of strings and an integer n

3. It returns a list that contains each string from the set repeated n times

items = {"banana", "apple", "pear"}
print(create_list(items, 2)) 
# order does not matter
# ['banana', 'banana', 'apple', 'apple', 'pear', 'pear']

write a function - solution

def create_list(items, n):
  new_list = [ ]
  for value in items:
    new_list.extend([value] * n)
  return new_list

def main():
  items = {"banana", "apple", "pear"}
  print(create_list(items, 2))  
  
main()

['apple', 'apple', 'pear', 'pear', 'banana', 'banana']

write a function

1. Its name is maximum
2. It takes a variable number of arguments: *values
3. It returns the highest value in values

assert maximum(1) == 1
assert maximum(2,4,6) == 6
assert maximum() == None

Write a function – solution

def maximum(*values):
  max = None
  for v in values:
    if max == None or v > max:
      max = v
  return max

def main():
  assert maximum(1) == 1
  assert maximum(2,4,6) == 6
  assert maximum() == None

main()

Can we change the order of max == None and v > max?

No we CANNOT. Try it on your own laptop.