Werkzeug

As I got more and more into Flask, I wanted to understand about Werkzeug.

Some helpful links:

• https://stackoverflow.com/questions/37004983/what-exactly-is-werkzeug
• https://stackoverflow.com/questions/14814201/can-i-serve-multiple-clients-using-just-flask-app-run-as-standalone

Azure ML SDK  uses ngix + gUnicorn  within its docker image:

• https://liupeirong.github.io/amlDockerImage/

 

 

ASP.NET Core web API

Some nice links.

Return Status Codes:

• https://docs.microsoft.com/en-us/aspnet/core/web-api/action-return-types?view=aspnetcore-3.0
• https://docs.microsoft.com/en-us/aspnet/core/web-api/advanced/conventions?view=aspnetcore-3.0
• https://www.talkingdotnet.com/return-http-status-code-from-asp-net-core-methods/

 

NPM v/s Bower – Intro

This is a nice intro to NPM.

• https://futurestud.io/tutorials/npm-quick-tips-1-install-packages

 

And here’s a nice intro to NPM.

• http://blog.teamtreehouse.com/getting-started-bower

 

This post captures some difference between npm and bower:

• http://stackoverflow.com/questions/18641899/what-is-the-difference-between-bower-and-npm

 

 

 

WordPress.com to Jekyll

Am trying to understand how to go about exporting my blog from WordPress.com to Jekyll.

My goal is to then host it on GitHub pages  under my user credentials.

Some references:

• http://hadihariri.com/2013/12/24/migrating-from-wordpress-to-jekyll/
• http://blog.8thcolor.com/en/2014/05/migrate-from-wordpress/
  • the above two were quite useful in understanding whats going on
• https://mmistakes.github.io/minimal-mistakes/
  • this theme seems quite good.
  • http://andybeger.com/2016/06/20/moving-from-wordpress-to-jekyll/
  • http://hadihariri.com/2013/12/24/migrating-from-wordpress-to-jekyll/
• http://karpathy.github.io/2014/07/01/switching-to-jekyll/
• http://www.girliemac.com/blog/2013/12/27/wordpress-to-jekyll/
• http://www.adamwadeharris.com/how-to-convert-a-wordpress-site-to-jekyll-with-github-pages/

Jekyll. Ubuntu 16.04

Jekyll has a very short ‘getting started’ guide:

Apparently that’s all that’s needed. However, my experience on Ubuntu 16.04 was more intense than this.

I kept hitting the following [issue](http://askubuntu.com/questions/793381/cant-install-rails-on-ubuntu-16-04)

Was almost about to give up on this thing before finding the links

• http://askubuntu.com/questions/793381/cant-install-rails-on-ubuntu-16-04
• http://stackoverflow.com/questions/38822133/ruby-on-rails-fails-on-fresh-ubuntu-mint-and-fedora-because-of-debug-inspector

 

Multithreading in Python

References:

• https://pymotw.com/2/threading/
• https://pymotw.com/2/logging/

Code:

• threads1
• threads2
• logging
• Exp_21_RRS_Train_Threads

Intro to Angular 2.0

I attended this meetup and got a basic understanding of Angular 2.0.

The interesting thing I realized is that there has been an immense amount of developments in the world of Web technologies. I would probably take me a week or two to come up-to speed with the developments in this field

• HTML/CSS/JavaScript/jQuery
• Bootstrap
• Node
• Express
• Angular
• React

In any case, the deck from the meetup can be found at  codefoster.com/ngmeetup

 

Web requests in Python

Recently tried making web requests in Python.

I used the urllib2 library for making 10 requests to the Azure Machine Learning web service.

Interestingly I found that using urllib2  was incurring a lot of latency.   I replaced urllib2 with the requests libarary and boom, the latency improved tremendously.

Tip:

• it seems the requests library  by default uses KeepAlive.  As such, it was not re-initiating the connection each time for the multiple requests. urllib2 on the other hand was re-initiating the connection for each request.
• Note:  the requests library is still making synchronous calls.




REST Calls in Python. JSON. Pandas.

I recently had to make REST calls in Python for sending data to Azure EventHub.

In this particular case I could not use the Python SDK to talk to EventHub. As I wrote down the code to make the raw REST calls, I came across several gems. Am listing them down below.

Tips:

• Use the python ‘requests’ library.
  • i am yet to figure out how to make async calls. can i use this library for async as well or would I have to use something else
• Sending JSON is way to go.
  • Don’t even try sending anything else
• Pandas has great functionality to convert  Series/DataFrames to JSON.
  • the ‘to_json’ function has awesome functionality including orient by ‘records’ etc
• Python has an awesome library called ‘json’ to deal with JSON data.
  • To deserialize ,use json.loads()
  • In particular,  to convert dict to JSON use  json.dumps().
  • Note: If you want to preserve the order, one would have to use ‘collections.OrderedDict’. Check this link

Check this out:

myj = '[{"reward":30,"actionname":"x","age":60,"gender":"M","weight":150,"Scored Labels":30.9928596354},{"reward":20,"actionname":"y","age":60,"gender":"M","weight":150,"Scored Labels":19.0217225957}]'

myj_l = json.loads(myj, object_pairs_hook=collections.OrderedDict)

myj_l
Out[177]:
[OrderedDict([(u'reward', 30), (u'actionname', u'x'), (u'age', 60), (u'gender', u'M'), (u'weight', 150), (u'Scored Labels', 30.9928596354)]),
 OrderedDict([(u'reward', 20), (u'actionname', u'y'), (u'age', 60), (u'gender', u'M'), (u'weight', 150), (u'Scored Labels', 19.0217225957)])]

for item in myj_l:
    print json.dumps(item)

{"reward": 30, "actionname": "x", "age": 60, "gender": "M", "weight": 150, "Scored Labels": 30.9928596354}
{"reward": 20, "actionname": "y", "age": 60, "gender": "M", "weight": 150, "Scored Labels": 19.0217225957}

References:

• http://docs.python-requests.org/en/master/

Code:

• rest_post.py

JSON DateTime

“DateTimes in JSON are hard.

The problem comes from the JSON spec itself: there is no literal syntax for dates in JSON. The spec has objects, arrays, strings, integers, and floats, but it defines no standard for what a date looks like.”

http://www.newtonsoft.com/json/help/html/datesinjson.htm

 

References:

• http://forums.asp.net/t/2032829.aspx?Newtonsoft+JSON+MicrosoftDateFormat+per+controller
• http://stackoverflow.com/questions/32138659/newtonsoft-json-isodatetimeconverter-and-dateformathandling
• http://stackoverflow.com/questions/10033612/prevent-json-net-4-5-from-appending-timezone-offset-when-using-microsoftdateform
• http://www.newtonsoft.com/json/help/html/datesinjson.htm
• http://www.newtonsoft.com/json/help/html/SerializeDateFormatHandling.htm
• http://www.newtonsoft.com/json/help/html/T_Newtonsoft_Json_DateFormatHandling.htm
• http://www.hanselman.com/blog/OnTheNightmareThatIsJSONDatesPlusJSONNETAndASPNETWebAPI.aspx

 

Code:

DecisionController