# wk15_1214_ch09_檔案與例外處理_B1003205醫放三謝彤
## [inclass practice]
```python
## chatGpt local jpg
import shutil
source_path = r'C:\zzz\111.png'
destination_path = r'C:\zzz\1.png'
# 複製文件
shutil.copyfile(source_path, destination_path)
print(f'已從 {source_path} 複製到 {destination_path}')
```
已從 C:\zzz\111.png 複製到 C:\zzz\1.png
```python
## chatGpt line png
import requests
import os
url = 'https://stickershop.line-scdn.net/stickershop/v1/sticker/230054638/android/sticker.png?v=1'
save_path = r'C:\zzz\3.jpg'
#response = requests.get(url, stream=True)
response = requests.get(url)
with open(save_path, 'wb') as file:
for chunk in response.iter_content(chunk_size=8192):
file.write(chunk)
print(f'已從 {url} 下載並保存到 {save_path}')
```
已從 https://stickershop.line-scdn.net/stickershop/v1/sticker/230054638/android/sticker.png?v=1 下載並保存到 C:\zzz\3.jpg
```python
## 課本原始檔
import requests, json, os
from bs4 import BeautifulSoup
url = 'https://store.line.me/stickershop/product/8991459/zh-Hant' #人的日常
url = 'https://store.line.me/stickershop/product/30084/zh-Hant'
html = requests.get(url)
sp = BeautifulSoup(html.text, 'html.parser')
#datas = sp.find_all('li', {'class':'mdCMN09Li FnStickerPreviewItem'})
datas = sp.find_all('li', {'class':'mdCMN09Li FnStickerPreviewItem static-sticker'})
# 建立目錄儲存圖片
images_dir= "line_image/"
if not os.path.exists(images_dir):
os.mkdir(images_dir)
for data in datas:
imginfo = json.loads(data.get('data-preview'))
id = imginfo['id']
imgfile = requests.get(imginfo['staticUrl'])
full_path = images_dir + id + '.png'
with open(full_path, 'wb') as f:
f.write(imgfile.content)
print(full_path)
```
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### 凱薩密碼
參考文件: https://github.com/CrypTools/CaesarCipher
```python
import string
import matplotlib.pyplot as plt
LETTERS = 'abcdefghijklmnopqrstuvwxyz,.() '
def encrypt(initial, shift):
initial = initial.lower()
output = ""
for char in initial:
if char in LETTERS:
output += LETTERS[(LETTERS.index(char) + shift) % len(LETTERS)]
return output
def decrypt(initial, shift):
initial = initial.lower()
output = ""
for char in initial:
if char in LETTERS: #密鑰(key)即shift量
output += LETTERS[(LETTERS.index(char) - shift) % len(LETTERS)]
return output
def plot_letter_frequency(text):
text = text.lower()
letter_count = {letter: 0 for letter in string.ascii_lowercase}
for char in text:
if char.isalpha():
letter_count[char] += 1
letters = list(letter_count.keys())
counts = list(letter_count.values())
plt.bar(letters, counts)
plt.xlabel('Letters')
plt.ylabel('Frequency')
plt.title('Letter Frequency in Text')
plt.savefig('./result.png')
## --------------- Main ------------------
message = input('請輸入要加密的訊息: ')
key = int(input('請輸入密鑰: '))
# 加密
cipher = encrypt(message, key)
print(f'\n加密結果: {cipher}')
# 解密
plain = decrypt(cipher, key)
print(f'\n解密結果: {plain}')
#字數統計
plot_letter_frequency(cipher)
```
請輸入要加密的訊息: ABCD
請輸入密鑰: 3
加密結果: defg
解密結果: abcd
## [afterclass practice]
### 綜合演練
1.以open(filename[,mode][,encode])開啟檔案，下列何者是mode參數預設的模式?
(A)讀取模式 (B)寫入模式 (C)附加模式 (D)以上皆是
Answer:(A)
2.Python提供何種內建函式，可以開啟指定的檔案，以便進行檔案內容的讀取、寫入或修改?
(A)file() (B)input() (C)open() (D)output()
Answer:(C)
3.下列何函式可以讀取一列字元?
(A)readable() (B)read() (C)readlines() (D)get(ch)
Answer:(B)
4.下列程式建立的檔案物件，可以執行何種動作?
(A)讀取 (B)寫入 (C)可讀取也可寫入 (D)以上皆非
Answer:(B)
```python
f=open('file1.txt','w')
f.write("Hello Python!")
f.close()
```
5.執行下列程式，下列顯示結果何者正確?
(A)x (B)y (C)xz (D)yz
Answer:(D)
```python
try:
print(x)
except:
print("y")
finally:
print("z")
```
y
z
6.open(filename,mode,encode)函式的參數中，其中只有哪一個參數是必填?
(A)filename (B)mode (C)encode (D)以上皆是
Answer:(A)
7.如果作業系統是繁體中文Window系統，預設的編碼為何?
(A)UTF-8 (B)cp950 (C)unicode (D)GB2312
Answer:(B)
8.下列有關readlines()的敘述，何者正確?
(A)會讀取全部文件內容 (B)以串列方式傳回 (C)包括「\n」跳列字元，甚至是隱含的字元 (D)以上皆是
Answer:(D)
9.執行下列程式，下列顯示結果何者正確?
(A)1 (B)n (C)變數不存在 (D)以上皆是
Answer:(A)
```python
n=1
try:
print(n)
except:
print("變數不存在!")
```
1
10.班上的除錯高手大匹，在他的程式中加入了錯誤的捕捉在try...except...finally敘述中，無論例外有沒有發生都會執行下列哪些程式區塊?
(A)try (B)except (C)finally (D)以上皆是
Answer:(C)
### 教學影音
try:程式碼A...except:程式碼B...else:程式碼C...finally:程式碼D\
else和finally不是必填的。\
程式碼A:用來執行並進行例外偵測\
程式碼B:若有發生例外，要執行的程式\
程式碼C:若沒發生例外，要執行的程式\
程式碼D:一定會執行的程式
## [self practice]
json套件是為了讓html解讀動態貼圖
sp是我們能解讀的格式
li是一張圖所佔據的項目
with open 可打開檔案並執行，執行結束後自動關掉，避免佔據過多記憶體
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