finished activity for lesson04

bookapp.py

@@ -1,24 +1,74 @@
 import re
-
+import traceback
 from bookdb import BookDB
 
 DB = BookDB()
 
 
 def book(book_id):
-    return "<h1>a book with id %s</h1>" % book_id
+    body = """<h1>{title}</h1>
+    <table>
+        <tr><th align='left'>Author:</th><td>{author}</td></tr>
+        <tr><th align='left'>Publisher:</th><td>{publisher}</td></tr>
+        <tr><th align='left'>ISBN:</th><td>{isbn}</td></tr>
+    </table>
+    <a href="/">Back to the list</a>
+    """
+    the_book = DB.title_info(book_id)
+    if the_book is None:
+        raise NameError
+    return body.format(**the_book)
 
 
 def books():
-    return "<h1>a list of books</h1>"
+    all_books = DB.titles()
+    body = ['<h1>My Bookself</h1>', '<ul>']
+    item_template = '<li><a href="/book/{id}">{title}</a></li>'
+    for book in all_books:
+        body.append(item_template.format(**book))
+    body.append('</ul>')
+    return '\n'.join(body)
 
+def book_router(path):
+    functions = {
+        '': books,
+        'book': book
+    }
+    # strip the last '/', then split the path into words by
+    # "/"
+    # so localhost:8080/ should be []
+    # localhost:8080/book/id1/ should be [book] [id1]
+    # localhost:8080/book/id2/ should be [book] [id2]
+    path = path.strip('/').split('/')
+    func_name = path[0]
+    func_args = path[1:]
+    try:
+        func = functions[func_name]
+    except KeyError:
+        raise NameError
+    finally:
+        return func, func_args
 
 def application(environ, start_response):
-    status = "200 OK"
     headers = [('Content-type', 'text/html')]
-    start_response(status, headers)
-    return ["<h1>No Progress Yet</h1>".encode('utf8')]
-
+    try:
+        path = environ.get("PATH_INFO", None)
+        if path is None:
+            raise NameError
+        func, args = book_router(path)
+        body = func(*args)
+        status = "200 OK"
+    except NameError:
+        status = '404 Not Found'
+        body = '<h1> 404 Not Found </h1>'
+    except Exception:
+        status = '500 Internal Server Error'
+        body = '<h1> Internal Server Error </h1>'
+        print(traceback.format_exc())
+    finally:
+        headers.append(('Content-len', str(len(body))))
+        start_response(status, headers)
+        return [body.encode('utf8')]
 
 if __name__ == '__main__':
     from wsgiref.simple_server import make_server