Lec 10 List Comp (Sets, Dicts)

• Accumulator pattern: Combining an amount of things into something
• Exercise
  • Ask user how many numbers they want to input
  • Asks for that many numbers
  • Prints min, max, and avg
  • No lists allowed

from typing import Optional
def print_min_max_avg() -> None:
    min_so_far: Optional[float] = None
    while True:
        try:
            count = int("How many nums?")
            break
        except ValueError:
            print("Bad boy.")
    for _ in range(count):
        number = float(input("Enter your number!"))
        sum += number
        if min_so_far is None or number < min_so_far:
            min_so_far = number

• Sets

  • Unordered
  • No repeated items
  • Operations:
    • Union: a | b
    • Union: a & b
    -
  • Find number of unique words in a given string:

    from typing import Set
    def get_num_unique_words(sentence: str) -> int:
    return len(set(sentence.split()))

  def check_for_equal_bdays(self) -> None
      birthdays: set[tuple[int, int]] = set()
      for _ in range(40):
          month = int(input("Month"))
          day = int(input("Day"))
          bday = (month, day)
          if birthday in birthdays
              return True
          birthdays.add(Birthday)
      return False

type({'hey'}) # set
type({}) # dict
type({'hi':'there'}) # dict

def get_word_counts(text: str) -> dict[str, int]:
    # how many times words appear
    word_counts: dict[str, int] = {}
    for word in text.split():
        #previous_count = word_counts.get(word, 0)
        word_counts[word] = wird_counts.get(word, 0) + 1
    return word_counts