如何使用Flask框架构建URL缩短器Web应用程序

pip install flask

1 from flask import Flask
2 app = Flask(__name__)
3
4 if __name__ == '__main__':
5
6 app.run(debug=True)

1 python app.py
2 Running on http://127.0.0.1:5000/ (Press CTRL+C to quit)
3 Restarting with stat
4 Debugger is active!
5 Debugger PIN: 123-456-789

1 CREATE TABLE urls (
2
3  id INTEGER PRIMARY KEY AUTOINCREMENT,
4
5  original_url TEXT NOT NULL,
6
7  short_url TEXT NOT NULL
8
9 );

1 from flask import Flask
2
3 import sqlite3
4
5
6
7 app = Flask(__name__)
8
9 app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///urls.db'
10
11 app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False #disable tracking modifications not needed in the tutorial
12
13 db = sqlite3.connect('urls.db')

1 import hashlib
2
3
4
5 def generate_short_url(original_url):
6
7   # Hash the original URL using MD5
8
9  hash_object = hashlib.md5(original_url.encode())
10
11  hash_hex = hash_object.hexdigest()
12
13
14
15  # Take the first 7 characters of the hash as the short URL
16
17  short_url = hash_hex[:7]
18
19
20
21  return short_url

1 def insert_url(original_url, short_url):
2
3  # Insert a new record into the urls table
4
5  cursor = db.cursor()
6
7  cursor.execute(
8
9   'INSERT INTO urls (original_url, short_url) VALUES (?, ?)',
10
11  (original_url, short_url)
12
13   )
14
15   db.commit()
16
17 cursor.close()

1 @app.route('/')
2
3 def redirect_url(short_url):
4
5  # Look up the original URL in the database
6
7 cursor = db.cursor()
8
9 cursor.execute(
10
11  'SELECT original_url FROM urls WHERE short_url = ?',
12
13   (short_url,)
14
15  )
16
17   result = cursor.fetchone()
18
19   cursor.close()
20
21
22
23  if result:
24
25     # Redirect to the original URL
26
27   return redirect(result[0])
28
29  else:
30
31   # Handle error if the short URL is not found
32
33 abort(404)

1 @app.errorhandler(404)
2
3  def page_not_found(error):
4
5   # Render a custom 404 error page
6
7   return render_template('404.html'), 404
8
9
10
11 @app.errorhandler(500)
12
13 def internal_server_error(error):
14
15  # Render a custom 500 error page
16
17   return render_template('500.html'), 500

1 
2
3 
4
5  
6
7  
8
9 
10
11  
12
13 
14
15  

16
17   Enter your URL:
18
19   
20
21  Shorten
22
23  
24
25  {% if urls %}
26
27   
Shortened URLs:
28
29   

30
31  {% for url in urls %}
32
33   
https://www.51cto.com/article/{{ url.short_url }} - {{ url.original_url }}
34
35   {% endfor %}
36
37   
38
39   {% endif %}
40
41  
42
43 

1 @app.route('/')
2
3 def index():
4
5  # Render the homepage template
6
7  urls = Url.query.order_by(Url.created.desc()).limit(10).all()
8
9   return render_template('index.html', urls=urls)
10
11
12
13  @app.errorhandler(404)
14
15 def page_not_found(error):
16
17  # Render the 404 error template
18
19  return render_template('404.html'), 404

1 @app.route('/')
2
3 def index():
4
5 # Retrieve the 10 most recently created URLs from the database
6
7  urls = Url.query.order_by(Url.created.desc()).limit(10).all()
8
9
10
11  # Render the homepage template with the list of URLs
12
13 return render_template('index.html', urls=urls)