Why not just use a parameter that can potentially be empty, with a default value of `None`?

    @app.route(&#39;/item/&lt;int:appitemid&gt;/&#39;)
    @app.route(&#39;/item/&lt;int:appitemid&gt;/&lt;path:anythingcanbehere&gt;&#39;)
    def show_item(appitemid, anythingcanbehere=None):

Yes - you use the following construct:

    @app.route(&#39;/item/&lt;int:appitemid&gt;/&lt;path:path&gt;&#39;)
    @app.route(&#39;/item/&lt;int:appitemid&gt;&#39;, defaults={&#39;path&#39;: &#39;&#39;})


See the snippet at http://flask.pocoo.org/snippets/57/

Constraints:  
1. Speed matters.  
2. I am allowed to ping once.  

I&#39;m debating whether to use Python or shellscripting. Is there a method faster than `bash`?

Here is the current code,

    for ip in $(seq int1 int2); do
        ping -c 1 xxx.xxx.xxx.$ip | grep &quot;bytes from&quot; &amp;
    done

Anything faster than this?

Fastest way to ping a network range and return responsive hosts?

We need to split a large live WMV video feed in small chunks all of the same size. We made a script that works fine doing this, except for one thing: the video chunks don&#39;t start with a key frame, so when playing most video chunks they don&#39;t display any image until a key frame from the original video is eventually reached.

Isn&#39;t there a way to tell ffmpeg to make the output video to start with a key frame?

Here is how our command lines look right now:

    ffmpeg.exe -i &quot;C:\test.wmv&quot; -ss 00:00:00 -t 00:00:05 -acodec copy -vcodec copy -async 1 -y  &quot;0000.wmv&quot;
    ffmpeg.exe -i &quot;C:\test.wmv&quot; -ss 00:00:05 -t 00:00:05 -acodec copy -vcodec copy -async 1 -y  &quot;0001.wmv&quot;
and so on...


How to split a video using FFMPEG so that each chunk starts with a key frame?

I am working with Flask 0.9. 

Now I want to route three urls to the same function:

    /item/&lt;int:appitemid&gt;
    /item/&lt;int:appitemid&gt;/ 
    /item/&lt;int:appitemid&gt;/&lt;anything can be here&gt;

The `&lt;anything can be here&gt;` part will never be used in the function.

I have to copy the same function twice to achieve this goal:

    @app.route(&#39;/item/&lt;int:appitemid&gt;/&#39;)
    def show_item(appitemid):
    
    @app.route(&#39;/item/&lt;int:appitemid&gt;/&lt;path:anythingcanbehere&gt;&#39;)
    def show_item(appitemid, anythingcanbehere):

Will there be a better solution?


Flask URL Route: Route Several URLs to the same function

I am working with Flask 0.9.
Now I want to route three urls to the same function:
<pre><code class="hljs language-javascript">/item/&#x3C;int:appitemid>
/item/&#x3C;int:appitemid>/ 
/item/&#x3C;int:appitemid>/&#x3C;anything can be here>
</code></pre>
The <code>&#x3C;anything can be here></code> part will never be used in the function.
I have to copy the same function twice to achieve this goal:
<pre><code class="hljs language-less">@app.route('/item/&#x3C;int:appitemid>/')
def show_item(appitemid):

@app.route('/item/&#x3C;int:appitemid>/&#x3C;path:anythingcanbehere>')
def show_item(appitemid, anythingcanbehere):
</code></pre>
Will there be a better solution?

I&#39;m running Pylint on some code, and receiving the error &quot;Too few public methods (0/2)&quot;. What does this message mean?

The [Pylint documentation][1] is not helpful:

&gt; Used when a class has too few public methods, so be sure it&#39;s really worth it.

  [1]: http://docs.pylint.org/features.html#id22




What does Pylint&#39;s &quot;Too few public methods&quot; message mean?

I have read the links below, but it doesn&#39;t address my question.&lt;br/&gt;
https://stackoverflow.com/questions/394809/python-ternary-operator (the question is about  condensing if-else statement to one line)&lt;br/&gt;

Is there an easier way of writing an if-elif-else statement so it fits on one line?&lt;br/&gt;
For example,


    if expression1:
       statement1
    elif expression2:
       statement2
    else:
       statement3

 Or a real-world example:

    if i &gt; 100:
        x = 2
    elif i &lt; 100:
        x = 1
    else:
        x = 0

I just feel if the example above could be written the following way, it could look like more concise.

    x=2 if i&gt;100 elif i&lt;100 1 else 0 [WRONG]


Putting an if-elif-else statement on one line?

Is it possible to directly declare a flask URL optional parameter?

Currently I&#39;m proceeding the following way:

    @user.route(&#39;/&lt;userId&gt;&#39;)
    @user.route(&#39;/&lt;userId&gt;/&lt;username&gt;&#39;)
    def show(userId, username=None):
        pass


How can I directly say that `username` is optional?

Can Flask have optional URL parameters?

I am a bit confused regarding data structure in python; `()`,`[]`, and `{}`. I am trying to sort a simple list, probably since I cannot identify the type of data I am failing to sort it.

My list is simple: `[&#39;Stem&#39;, &#39;constitute&#39;, &#39;Sedge&#39;, &#39;Eflux&#39;, &#39;Whim&#39;, &#39;Intrigue&#39;]` 

My question is what type of data this is, and how to sort the words alphabetically?

Python data structure sort list alphabetically

I have a long list of lists of the following form ---

    a = [[1.2,&#39;abc&#39;,3],[1.2,&#39;werew&#39;,4],........,[1.4,&#39;qew&#39;,2]]

i.e. the values in the list are of different types -- float,int, strings.How do I write it into a csv file so that my output csv file looks like

    1.2,abc,3
    1.2,werew,4
    .
    .
    .
    1.4,qew,2




Writing a Python list of lists to a csv file

I am using `url_for` to generate a redirect URL when a user has logged out:

    return redirect(url_for(&#39;.index&#39;, _external=True))

However, when I changed the page to a *https* connection, the `url_for` still gives me *http*.

I would like to explicitly ask `url_for` to add *https* at the beginning of a URL.

Can you point me how to change it? I looked at Flask docs, without luck.

Flask url_for generating http URL instead of https

In AngularJS, I see sometimes we use `$state.transitionTo()` and sometimes we use `$state.go()`. Can anyone tell me how they differ and when one should be used over the other?

Difference between $state.transitionTo() and $state.go() in Angular ui-router

I have been thinking and I am confused with the routing between Client and Server. Suppose I use ReactJS for server-side rendering before sending the request back to web browser, and use react-router as a client-side routing to switch between pages without refreshing as SPA.

What comes to mind is:

- How are the routes interpreted? For example, a request from Home page (`/home`) to Posts page (`/posts`)
- Where does the routing go, on server-side or client?
- How does it know how it is processed?



Client Routing (using react-router) and Server-Side Routing

I don&#39;t understand what the purpose of using an **IndexRoute** and **IndexLink**. It seems that in any case the code below would have selected the Home component first unless the About path was activated.

    &lt;Route path=&quot;/&quot; component={App}&gt;
      &lt;IndexRoute component={Home}/&gt;
      &lt;Route path=&quot;about&quot; component={About}/&gt;
    &lt;/Route&gt;

 vs   

    &lt;Route path=&quot;/&quot; component={App}&gt;
      &lt;Route path=&quot;home&quot; component={Home}/&gt;
      &lt;Route path=&quot;about&quot; component={About}/&gt;
    &lt;/Route&gt;

What&#39;s the advantage/purpose here of the first case?

React-Router : What is the purpose of IndexRoute?

I&#39;d like to make a redirection in `Vue.js` similar to the vanilla javascript

    window.location.href = &#39;some_url&#39;

How could I achieve this in Vue.js?


Vue.js redirection to another page

I have a Flask application that works well and produces an occasional error, which is visible when it is running with `debug=True`: 

    if __name__ == &#39;__main__&#39;:
        app.run(debug=True)

I get useful error messages such as:

    Traceback (most recent call last):
      File &quot;./main.py&quot;, line 871, in index_route
        
    KeyError: &#39;stateIIIII&#39;


I would like to get error messages like these saved to a file when I run the application in production (using Lighttpd + fastcgi).

After looking at various StackOverflow questions (http://flask.pocoo.org/docs/errorhandling/, http://docs.python.org/2/library/logging.html, etc.); the Flask mailing list; and a few blogs, it seems there is no easy way just to send all the great error messages to a file - I need to use the Python logging module to customise things. So I came up with the following code.

At the top of my application file I have various imports followed by:

    app = Flask(__name__)
    
    if app.debug is not True:	
    	import logging
    	from logging.handlers import RotatingFileHandler
    	file_handler = RotatingFileHandler(&#39;python.log&#39;, maxBytes=1024 * 1024 * 100, backupCount=20)
    	file_handler.setLevel(logging.ERROR)
    	app.logger.setLevel(logging.ERROR)
    	app.logger.addHandler(file_handler)

I have then put the code for each route in a try/except statement and use traceback to work out which line the error came from and print a nice error message:

    def some_route():
    	try:
    		# code for route in here (including a return statement)
    		
    	except:
    		exc_type, exc_value, exc_traceback = sys.exc_info()
    		app.logger.error(traceback.print_exception(exc_type, exc_value, exc_traceback, limit=2))
    		return render_template(&#39;error.html&#39;)

And then right at the end of the file I remove the `debug=True` statement. Though I don&#39;t think I need to do that as the application is being run by a fastcgi server(?) when it is run in production. The last two lines of my application code look like this:

    if __name__ == &#39;__main__&#39;:
    	app.run()


I am struggling to get this working. I think the best I have managed is to get a single error log message to be saved in the file using (`app.logger.error(&#39;test message&#39;)` ), but it only prints that one message. An attempt to log another error directly after that one is simply ignored.

How do I write Flask&#39;s excellent debug log message to a file in production?

After reading many similar sounding problems and the relevant Flask docs, I cannot seem to figure out what is generating the following error upon submitting a form:

&gt; 400 Bad Request
&gt;
&gt; The browser (or proxy) sent a request that this server could not understand.

While the form always displays properly, the bad request happens when I submit an HTML form that ties to either of these functions: 

    @app.route(&#39;/app/business&#39;, methods=[&#39;GET&#39;, &#39;POST&#39;])
    def apply_business():
        if request.method == &#39;POST&#39;:    
            new_account = Business(name=request.form[&#39;name_field&#39;], email=request.form[&#39;email_field&#39;], account_type=&quot;business&quot;, 
                q1=request.form[&#39;q1_field&#39;], q2=request.form[&#39;q2_field&#39;], q3=request.form[&#39;q3_field&#39;], q4=request.form[&#39;q4_field&#39;], 
                q5=request.form[&#39;q5_field&#39;], q6=request.form[&#39;q6_field&#39;], q7=request.form[&#39;q7_field&#39;],
                account_status=&quot;pending&quot;, time=datetime.datetime.utcnow())
            db.session.add(new_account)
            db.session.commit()
            session[&#39;name&#39;] = request.form[&#39;name_field&#39;]    
            return redirect(url_for(&#39;success&#39;))
        return render_template(&#39;application.html&#39;, accounttype=&quot;business&quot;)          
    
    @app.route(&#39;/app/student&#39;, methods=[&#39;GET&#39;, &#39;POST&#39;])
    def apply_student():    
        if request.method == &#39;POST&#39;:    
            new_account = Student(name=request.form[&#39;name_field&#39;], email=request.form[&#39;email_field&#39;], account_type=&quot;student&quot;, 
                q1=request.form[&#39;q1_field&#39;], q2=request.form[&#39;q2_field&#39;], q3=request.form[&#39;q3_field&#39;], q4=request.form[&#39;q4_field&#39;], 
                q5=request.form[&#39;q5_field&#39;], q6=request.form[&#39;q6_field&#39;], q7=request.form[&#39;q7_field&#39;], q8=request.form[&#39;q8_field&#39;], 
                q9=request.form[&#39;q9_field&#39;], q10=request.form[&#39;q10_field&#39;],
                account_status=&quot;pending&quot;, time=datetime.datetime.utcnow())
            db.session.add(new_account)
            db.session.commit()
            session[&#39;name&#39;] = request.form[&#39;name_field&#39;]    
            return redirect(url_for(&#39;success&#39;)) 
        return render_template(&#39;application.html&#39;, accounttype=&quot;student&quot;)

The relevant part of HTML is

&lt;!-- language: lang-html --&gt;

    &lt;html&gt;
    &lt;head&gt;
        &lt;title&gt;apply&lt;/title&gt;
    &lt;/head&gt;
    &lt;body&gt;
        {% if accounttype==&quot;business&quot; %}
        &lt;form action=&quot;{{ url_for(&#39;apply_business&#39;) }}&quot; method=post class=&quot;application_form&quot;&gt;
        {% elif accounttype==&quot;student&quot; %}
        &lt;form action=&quot;{{ url_for(&#39;apply_student&#39;) }}&quot; method=post class=&quot;application_form&quot;&gt;     
        {% endif %} 
        &lt;p&gt;Full Name:&lt;/p&gt;
        &lt;input name=&quot;name_field&quot; placeholder=&quot;First and Last&quot;&gt;
        &lt;p&gt;Email Address:&lt;/p&gt;
        &lt;input name=&quot;email_field&quot; placeholder=&quot;your@email.com&quot;&gt;
        ...

The problem for most people was not calling ``GET`` or ``POST``, but I am doing just that in both functions, and I double checked to make sure I imported everything necessary, such as ``from flask import request``. I also queried the database and confirmed that the additions from the form weren&#39;t added.

In the Flask app, I was requesting form fields that were labeled slightly different in the HTML form. Keeping the names consistent is a must. More can be read at this question https://stackoverflow.com/questions/8552675/form-sending-error-flask

What is the cause of the Bad Request Error when submitting form in Flask application?

My problem is that with the given code:

    from flask import Flask, request

    app = Flask(__name__)

    @app.route(&quot;/&quot;)
    def hello():
        return str(request.values.get(&quot;param&quot;, &quot;None&quot;))

    app.run(debug=True)

and I visit:

    http://localhost:5000/?param=a&amp;param=bbb

I should expect an output of [&#39;a&#39;, &#39;bbb&#39;] except Flask seems to only accept the first param and ignore the rest.

Is this a limitation of Flask? Or is it by design?

Get multiple request params of the same name

I am new in both flask and sqlalchemy, I just start working on a flask app, and I am using sqlalchemy for now. I was wondering if there is any significant benefit I can get from using flask-sqlalchemy vs sqlalchemy. I could not find enough motivations in &lt;http://packages.python.org/Flask-SQLAlchemy/index.html&gt; or maybe I did not understand the value!! I would appreciate your clarifications.

Content Type	Original Author	Original Content on Stackoverflow
Question	Gaby Solis	View Question on Stackoverflow
Solution 1 - Python	Amber	View Answer on Stackoverflow
Solution 2 - Python	Jon Clements	View Answer on Stackoverflow

Flask URL Route: Route Several URLs to the same function

Python Problem Overview

Python Solutions

Solution 1 - Python

Solution 2 - Python

How to split a video using FFMPEG so that each chunk starts with a key frame?

Fastest way to ping a network range and return responsive hosts?

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