Day 8 - Function & Caesar Cipher

learning from 100 Days of Code: The Complete Python Pro Bootcamp for 2022

(1) Positional Argument

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

my_function(1,2,3)

(2) Keyword Argument

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

my_function(b=2,c=3,a=1)

a,b,c = 1,2,3
Parameter = Argument

# Paint Area Calculator

import math #無條件進位的function
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)

# Prime Numbers

def prime_checker(number):
    nature_num = 2
    not_prime = False
    while nature_num **2 < number:

        if number % nature_num == 0:
            print(f"It's not a prime number.")
            not_prime = True
            break

        nature_num +=1
    if not_prime == False:
        print(f"It's a prime number.")

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

## Caesar Cipher 00
# 前置資料

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']

# 重複兩遍，index只會讀取第一個找到的字元

## Caesar Cipher 01
# step1 設定編碼－老師教學版本(精簡多了!)

def caesar(start_text, shift_amount, cipher_direction):
  end_text = "" #字串以 += 增加字元；List以 append 增加項目
  if cipher_direction == "decode":
    shift_amount *= -1
  for char in start_text:
    # for loop 可以直接挑出String中的每個字元
    # 可以在loop內轉換單字，一起轉譯
    if char in alphabet:
      position = alphabet.index(char)
      new_position = position + shift_amount
      end_text += alphabet[new_position]
    # 如果不是字母，就會直接輸出
    else:
      end_text += char

  print(f"Here's the {cipher_direction}d result: {end_text}")

## Caesar Cipher 02
# step2 執行程式－老師教學版本

print(art.logo)
play_again = True

while play_again:
  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"))
  #　Debug : 如果輸入數字超過26，會取餘數
  shift = shift % 26
  caesar(start_text=text, shift_amount=shift, cipher_direction=direction)

  ask_again = input("Type \'yes\' if you want to go again. Otherwise type \'no\'.").lower()
  # 如果不繼續了，就會跳出 while loop
  if ask_again == "no":
    print("Goodbye")
    play_again =  False

## Caesar Cipher 
# step1 設定編碼－自己練習版本(很囉唆)

# 定義編碼程式
def encrypt(shift_way):
  if shift_way == "encode":
    for num_shift in range(shift):
      alphabet.append(alphabet[0])
      del alphabet[0]
  if shift_way == "decode":
    for num_shift in range(shift):
      alphabet.insert(0,alphabet[25])
      del alphabet[26]

location = []
new_text = ""

# 先找出原單字的位置(list 搭配 append)
for letter in list(text):
  location.append(alphabet.index(letter))

# 編碼
encrypt(direction)

# 再依據對應位置找出新單字(""可用+=直接輸出單字)
for new_letter in location:
  new_text += alphabet[new_letter]

print(f"The {direction}d text is {new_text}")