[udemy] python 부트캠프 _ section 8_함수의 매개변수와 카이사르 암호

01. 입력 값이 있는 함수

# Review: 
# Create a function called greet(). 
# Write 3 print statements inside the function.
# Call the greet() function and run your code.

def greet():
  print("Hello")
  print("How do you do?")
  print("Isn't the weather nice today?")

greet()

def my_function(something):
    # Do this with something
    # Then do this
    # Finally do this 
 my_function(123)
 
 def greet_with_name(name):
  print(f"Hello {name}")
  print(f"How do you do? {name}")

greet_with_name("yo")

• parameter : 데이터 이름으로 함수 안에서 그 변수가 사용될 때 쓰임. (ex.something)
• argument: 함수로 전달되고 호출되는 데이터.(ex.123)

02. 위치 인자와 키워드 인자

# function with more than 1 input
def greet_with(name, location):
  print(f"Hello, {name}")
  print(f"What is it like in {location}")  

greet_with("you","seoul")

def my_function(a,b,c):
    # Do this with a
    # Then do this with b
    # Finally do this with c

• argument 들은 위치에 따라서 정해진다. 의도한 바와 다르게 함수가 작동되면 맞는 위치에 변수를 입력했는지 확인해야 함.
• 키워드 인자 : 함수에 아큐먼트들은 이름과 등호를 이용해 할당하는 것 (a = 3, c = 1, b = 2)

# function with more than 1 input
def greet_with(location, name):
  print(f"Hello, {name}")
  print(f"What is it like in {location}")  

greet_with(name = "you",location ="seoul")

03. quiz _ wall painting

import math

def paint_calc(height,width,cover):
  num_of_cans = math.ceil((height * width) / cover)
  print(f" You\'ll need {num_of_cans} cans of paint.")

test_h = int(input("Height of wall: "))
test_w = int(input("Width of wall: "))
coverage = 5
paint_calc(height=test_h, width=test_w, cover=coverage)

04. quiz _ Number Checker

def prime_checker(number):
  is_prime = True
  for i in range(2, number):
    if number % i == 0:
     is_prime = False
  if is_prime:
    print("It's a prime number.")
  else:
    print("It's not a prime number.")

n = int(input("Check this number: "))
prime_checker(number=n)

05. quiz _ encode

alphabet = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z','a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z']

direction = input("Type 'encode' to encrypt, type 'decode' to decrypt:\n")
text = input("Type your message:\n").lower()
shift = int(input("Type the shift number:\n"))

#TODO-1: Create a function called 'encrypt' that takes the 'text' and 'shift' as inputs.
def encrypt(plain_text,shift_amount):
  cipher_text = ""
  for letter in plain_text:
    position = alphabet.index(letter)
    new_position = position + 5
    new_letter = alphabet[new_position]
    cipher_text += new_letter
  print(f"The encoded text is {cipher_text}.")


encrypt(plain_text = text, shift_amount=shift)

06. quiz _ decode

alphabet = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z']

direction = input("Type 'encode' to encrypt, type 'decode' to decrypt:\n")
text = input("Type your message:\n").lower()
shift = int(input("Type the shift number:\n"))


def encrypt(plain_text, shift_amount):
  cipher_text = ""
  for letter in plain_text:
    position = alphabet.index(letter)
    new_position = position + shift_amount
    cipher_text += alphabet[new_position]
  print(f"The encoded text is {cipher_text}")


def decrypt(cipher_text, shift_amount):
  plain_text=""
  for letter in cipher_text:
    position = alphabet.index(letter)
    new_position = position - shift_amount
    plain_text += alphabet[new_position]
  print(f"The decoded text is {plain_text}.")
  
if direction == "encode":
  encrypt(plain_text = text, shift_amount=shift)
elif direction == "decode":
  decrypt(cipher_text = text, shift_amount=shift)

07. quiz _ caesar

alphabet = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z']

direction = input("Type 'encode' to encrypt, type 'decode' to decrypt:\n")
text = input("Type your message:\n").lower()
shift = int(input("Type the shift number:\n"))

def caesar(start_text, shift_amount, cipher_direction):
  end_text = ""
  if cipher_direction == "decode":
      shift_amount *= -1 
  for letter in start_text:
    position = alphabet.index(letter)
    new_position = position + shift_amount
    end_text += alphabet[new_position]
  print(f"Here's the {direction}d result: {end_text}.")

caesar(start_text = text, shift_amount = shift, cipher_direction = direction)

• if ~ shift_amount *=1 이 부분을 for 반복문 안에 넣어주게 되면, shift_amount는 계속해서 -1이 곱해지므로 제대로 된 값이 산출되지 않는다. (암호화 -> 복호화 -> 암호화-> 복호화) 이런식으로 계속 반복하게 되므로, for 반복문 밖으로 빼준다.

08. ui develop

alphabet = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z']

def caesar(start_text, shift_amount, cipher_direction):
  end_text = ""
  if cipher_direction == "decode":
    shift_amount *= -1
  for char in start_text:
    if char in alphabet:
      position = alphabet.index(char)
      new_position = position + shift_amount
      end_text += alphabet[new_position]
    else:
      end_text += char
  print(f"Here's the {cipher_direction}d result: {end_text}")

from art import logo
print(logo)

should_end = False
while not should_end:

  direction = input("Type 'encode' to encrypt, type 'decode' to decrypt:\n")
  text = input("Type your message:\n").lower()
  shift = int(input("Type the shift number:\n"))
  shift = shift % 26

  caesar(start_text=text, shift_amount=shift, cipher_direction=direction)

  restart = input("Type 'yes' if you want to go again. Otherwise type 'no'.\n")
  if restart == "no":
    should_end = True
    print("Goodbye")