bottle route regular expression

Routing¶

As you have learned before, routes are used to map URLs to callback functions. These functions are executed on every request that matches the route and their return value is returned to the browser. You can add any number of routes to a callback using the route() decorator.

<span class="kn">from</span> <span class="nn">bottle</span> <span class="kn">import</span> <span class="n">route</span>

<span class="nd">@route</span><span class="p">(</span><span class="s">'/'</span><span class="p">)</span>
<span class="nd">@route</span><span class="p">(</span><span class="s">'/index.html'</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">index</span><span class="p">():</span>
    <span class="k">return</span> <span class="s">"<a href='/hello'>Go to Hello World page</a>"</span>

<span class="nd">@route</span><span class="p">(</span><span class="s">'/hello'</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">hello</span><span class="p">():</span>
    <span class="k">return</span> <span class="s">"Hello World!"</span>

As you can see, URLs and routes have nothing to do with actual files on the web server. Routes are unique names for your callbacks, nothing more and nothing less. All URLs not covered by a route are answered with a “404 Page not found” error page.

 

Dynamic Routes¶

Bottle has a special syntax to add wildcards to a route and allow a single route to match a wide range of URLs. These dynamic routes are often used by blogs or wikis to create nice looking and meaningful URLs such as /archive/2010/04/21 or /wiki/Page_Title. Why? Because cool URIs don’t change. Let’s add a :name wildcard to our last example:

<span class="nd">@route</span><span class="p">(</span><span class="s">'/hello/:name'</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">hello</span><span class="p">(</span><span class="n">name</span><span class="p">):</span>
    <span class="k">return</span> <span class="s">"Hello </span><span class="si">%s</span><span class="s">!"</span> <span class="o">%</span> <span class="n">name</span>

This dynamic route will match /hello/alice as well as /hello/bob. Each URL fragment covered by a wildcard is passed to the callback function as a keyword argument so you can use the information in your application.

Normal wildcards match everything up to the next slash. You can add a regular expression to change that:

<span class="nd">@route</span><span class="p">(</span><span class="s">'/object/:id#[0-9]+#'</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">view_object</span><span class="p">(</span><span class="nb">id</span><span class="p">):</span>
    <span class="k">return</span> <span class="s">"Object ID: </span><span class="si">%d</span><span class="s">"</span> <span class="o">%</span> <span class="nb">int</span><span class="p">(</span><span class="nb">id</span><span class="p">)</span>

As you can see, the keyword argument contains a string even if the wildcard is configured to only match digits. You have to explicitly cast it into an integer if you need to.

reference bottle doc

example:

@route("/news/:filename#p\d+and[\s\S]*?\.html#")

@view("article/detail")

def article_detail(filename):

    print filename

    match = re.search(r"^p(\d+)and[\s\S]*?\.html$", filename)

    id=None

    if match:

        id=int(match.group(1))

        print "id=%s"%id

        a=Article.get(id)

        if a is not None:

            b=Article.query.filter_by(id < 20).one()

            if b is None:

                print "b None"

            else:

                print "b not None"

            return {"article":a}

        else:

            return {}

    return {}