Saturday, August 25, 2018

Getting Started Coding Amazon Alexa Skills for Developers

Getting Started

First read our blog post on how to get started with Alexa Skill building or watch our youtube video on the topic

Visit the Alexa Skill Store to see more than 25000 skills available.

Alexa Skill Persona

Monetizing Your Alexa Skill - Earn Money with Your Alexa Skill

Deep Drive for In Game Purchase

Amazon Alexa Skill Developer Community, Developer Support, Developer Relations

Amazon rewards developers with promotions and token rewards

Alexa devday for a city near you

Super developer award, developer incentives and promotions

Developer 3 skill promotion

Amazon Alexa Skill Dev Tools

Alexa Setting API for timezone, temperature and unit personalization, localization for example for sports event this really matters.

Amazon Alexa Skill Development Best Practice

Naming your Alexa Skill

Improve customer engagement

Diaglog Management

Thursday, August 23, 2018

ImportError: No module named flaskr - Python Flask Flaskr Tutorial Error Debug

Error Message

/flaskr/", line 1, in <module> from .flaskr import app ImportError: No module named flaskr 

Related github issues

Issue 2058
Issue 1902
Issue 2437 The example flaskr can't easily be run by a beginner in Flask framework

Issue Summary

Ran into the above error because some files are put into the wrong directory and need to be moved.

Proposed solution

Better understanding of the tutorial folder structure. Here's a better diagram than the original.

├── flaskr
│   ├──
│   ├──
│   ├── schema.sql
│   ├── static
│   └── templates

The indentation of the original tutorial is hard to read!

after a successful $flask run command
you will get this updated folder structure below:

├── flaskr
│   ├──
│   ├── __init__.pyc
│   ├──
│   ├── flaskr.pyc
│   ├── schema.sql
│   ├── static
│   └── templates
├── flaskr.egg-info
│   ├── PKG-INFO
│   ├── SOURCES.txt
│   ├── dependency_links.txt
│   ├── requires.txt
│   └── top_level.txt

happy coding.


I found the Flaskr tutorial through Nicole White's talk about Neo4j and Flaskr. Plus Flask is a popular python web framework. I have always wanted to code a helloworld. 

Additional documentation

Friday, August 17, 2018

Password protect and zip compress files on Mac

The following step is only recommended for developers who have experience working in the command line. This is the build-in zip compress and password protect function in Mac, so it is free.

It's very difficult if not impossible to undo command line changes. So please, only use this option if you are familiar with command line scripts.

Data Science beyond the basics

Exploratory Data Analysis

  • Histogram plotting, input is a list of distributions we want to plot,  specify bins, can also weigh each sample differently, it doesn't have to be count 1. hist function can return values.  How many items in each bin, and the plot. 
  • It is also important to do feature extraction, simply the data, reduce computational cost, dimensionality reduction before feeding data into a machine learning algorithm. Algorithms will run faster, more efficiently, use less memory space, and even perform better, in some cases. 
  • Anomaly detection, outlier detection to handle or remove outliers and abnormality in the data to help the model generalize better and be a more accurate representation. 

Machine Learning

Machine Learning is emerging as a popular field of data science. It has predictive power, employs applied statistics and pattern recognition technologies.

Machine learning is taking data mining to the next level.

Major machine learning tasks include classification, regression and clustering.

Questions that Business Analysts and Decision Makers are Interested In

  • Who are the best customers? aka Who are the customers with the best Customer Life Value
  • Causal relationship: 
    • Results of recent experiments (More prevalent in Startup Culture)
    • Hypothesis if one segmentation is actually different from another
    • Is the result significant or is it random chance
    • Please note that causal relationship determination requires controlled studies to control for extraneous variables. In many industries, such as biotech, statistical significance is a must, a prerequisite for next step analysis or more business investments. 
    • Demo graphics of customers. Summary statistics, customer segmentation and more. 
    • How to measure profitability and other Key Performance Indicators (KPI)

Statistical Hypothesis Testing

Python for Data Science

  • Use conda command similar to pip for installing and launching packages
  • Anaconda comes with a wonderful Python IDE called Spyder

Scientific Computing using Scipy

  • Scipy.integral.quad using the quad method to compute integral function to compute, lower bound, first bound, a tuple, returns an approximation of the result and how much error

Becoming a Data Engineer

Data engineer takes care of data quality. Provide data fast, reliably. 
For example, data funnel starts when installing a javascript tag, gather user browsing data. End with a Saas that client can visualize the data.
Things that can happen in between data gathering , aggregation, storage and delivery. ContentSquare collects browser data so that grows fast. 70 million web pages per day, 3 terabytes of new data each month, 10**15 peta bytes per year. kafka, spark elastic, scala akka

Sunday, August 5, 2018

Lifehack Productivity Tips for Business Bay Area Professionals No.101

General Productivity
  • Did you know that having a daily routine improves efficiency and productivity? Mark Zuckerberg of Facebook famously wear the same grey shirt and hoodie on a daily basis to simplify wardrobe choices and save minutes each day. 
  • Automate everything: use API connectors to connect applications such as Gmail, Shopify and Trello without coding: Zapier, IFTTT, Do Button
  • Fix your iphone, your glasses your gadgets DIY style
  • Tool for Youtube Creators SoundCloud audio editing
  • Join an online initiative to go complaint free for one month and induce positivity in your life
  • Easily distracted? Having trouble finishing meaningful tasks? Try a 30/30 timer rule: switching tasks every 30 minutes. There are iOS apps that time you and chime for you to make a switch and move on.

Password Security and Privacy

  • Check if your email has been hacked
  • Controls what google knows about you

Social Network, Social Marketing and Growth Lifehacks

  • Use Tweepi to flush Twitter followers that are inactive or don't follow you back

Personal Finance Productivity

  • Use a stock, mutual fund screener to find stocks and funds that match your investment goals for your 401K plan

Developer Productivity:

  • Pair programming for productivity - AirPair and Pivot Labs, a premium development consulting agency for startups and new technology companies, talk about pair programming for developer productivity
  • Use code lint, code validation, and auto formatting (such as Android Studio code formatting) to get error free codes
  • Always look for shortcuts and do more things faster. Some developers even use fast notetaking apps like notational velocity and combine it with hot keys to shave fraction of seconds off their daily routine. 
  • Code a mobile app without learning iOS development or Android ionic framework

Startup Productivity

  • Use prototype and wireframes as visual aid to communicate product visions and designs, clearly. 
  • Did you know that having a 3D printed prototype generate 3x more feedback for architecture and physical product designers than just having a concept drawing? 
  • Did you know that famous universities like Stanford teach students to print or draw iOS UIs and designs on paper and walk user through imaginary steps to get design feedback before they code?
  • Looking for great business ideas? Use a startup name or domain generator to get inspired!
  • Google design often teaches paper prototyping - fast, easy-to-use and effective

    This Week in Silicon Valley Byte Size Newsletter No.101

    Udacity Launches AI for trading with WorldQuant, also its hiring partner. Ready to do artificial intelligence for fintech, this may be your nanodegree! What's the ultimate dream? Probably join a quantitative traded hedge fund, eventually. It is said that a little less than 30% of all US trades are done by computers. Specifically you want python for finance and historical data skills.

    Author Adam Fisher launches Valley of Genius as told by the hackers, founders, and freaks who made it. If you like HBO's Silicon Valley, you will probably like these unicorn and innovator stories of Silicon Valley

    Great Escape! Medium is running an August author challenge: tell Medium why and how you quit your job! Your story may be featured. See this challenge post by Medium's editor.

    What does it feel like to be Steve Job's daughter? Her memoir now available for readers. See this article on Vanity Fair.

    Youtube Machine Learning Artificial Intelligence celebrity Sraj wants to start his own School of AI. He wants it to be a "nonprofit". Strange but true. He's now recruiting Deans to head cities.

    Business Intelligence Data Warehousing BIDW Basics 101

    BIDW may employ more stable, heavy duty and less flexible architecture, schema and data store than startups in the Silicon Valley. Such may be a sacrifice for security, stability which many fortune companies rely on.

    Structured Query Language (SQL)

    Despite the popularity of many new data stores and technologies such as Hadoop, Spark, Pandas etc, many companies still require Business Analysts to be fluent in sql. Never forget SQL.

    Graphical User Interface (GUI)

    GUI interface helps business users query and drill data without the help of the development department. The schema and database are still designed and implemented by dev.

    Online Analytical Processing (OLAP)

    Provides a GUI to query platform for business users to do data explorations with minimum help from dev department. 

    Analysts and decision makers can quickly and efficiently do data analysis and ad hoc reporting without too much help from a data scientist or database administrator. 

    The schema, reports, and drilling depth may need to be pre-planned, designed and tested before being released to business users.

    This is also a large scale system, suitable for companies such as Macy's, Gap, Walmart which have millions of new sales record per hour. 

    OLAP is for data exploration by large businesses.

    Data Warehousing 

    Data Warehousing is a serious challenge for large companies with many transactional records, product offerings across many departments. 

    Many DW providers can also provide integrated data mining, business intelligence services build on top of proprietary DW hardware (including server stack) and software.

    Best Practice

    • Sales teams on-the-road often needs faster, better data information on mobile devices to seal a deal. Don't be surprised if they get mad when numbers are off! They bring home the dough. 

    Questions that Business Analysts and Decision Makers are Interested In

    • Who are the best customers? aka Who are the customers with the best Customer Life Value
    • Causal relationship: 
      • Results of recent experiments (More prevalent in Startup Culture)
      • Hypothesis if one segmentation is actually different from another
      • Is the result significant or is it random chance
      • Please note that causal relationship determination requires controlled studies to control for extraneous variables. In many industries, such as biotech, statistical significance is a must, a prerequisite for next step analysis or more business investments. 
      • Demo graphics of customers. Summary statistics, customer segmentation and more. 
      • How to measure profitability and other Key Performance Indicators (KPI)

    SQL Basics 101


    The Equivalent of HelloWorld of SQL

    SELECT *
    FROM table_name

    Select all columns and rows from a table. In real life practice, we may want to avoid using SELECT * because it may be asking and displaying a lot of unnecessary records utilizing our precious computing resource, especially for large systems, companies with large databases. 

    A Basic Select Statement

    SELECT ProductID, Name
    FROM Product
    WHERE Price > 2.00

    A Fancier Select Statement


    The *  means all, specifically all columns and rows in this statement. All columns and all rows will be returned. 

    An Advanced Select Statement with Join Statement

    SELECT p.[Name] AS ProductName,
    c.[Name] AS CategoryName,
    FROM SalesLT.Product AS p
    JOIN SalesLT.ProductCategory AS c
    ON p.ProductCategoryID = c.ProductCategoryID;

    An Insert Statement

    INSERT INTO table_name (column1, column2, column3, ...)
    VALUES (value1, value2, value3, ...);

    Useful SQL interview skills

    Be able to read and comprehend SQL scripts

    Be able to compose advanced sql queries including aggregation, slicing and dicing.

    Advanced SQL Query Select Count and Group By

    It's easy to use SQL to display all the data columns and rows. But that's not practical. It's not practical for the business user to get the entire database, nor is it memory efficient. 

    How to view aggregate data? Use Group By, don't forget to use Count() too, else the result is again not meaningful. 


    Group By helps aggregate and filter out data. In this case we are interested in aggregating data by State in the Customers table. What kind of state wide information are we trying to get? We are trying to count the number of customers in each state, as measured by customer_id. In addition, once data is aggregated, order the results in a descending order by count(customer_id) the largest count to the smallest. 

    Compare a Select all statement which just returns all the data rows
    Select Count() and Group By statement that aggregates data by country

    SQL is great for the following queries:

    • SQL Segmentation example, analyze by location, select * from sales group by location

    Additional Tools

    Why should you learn SQL - common SQL usage

    Swift iOS Development Core Data uses sqlite as a persistent data store.

    Alternatives to SQL language, sqlite, and relational databases
    • ORM and ActiveRecords used in Rails
    • Hadoop uses HIVE is a SQL like language
    • Spark and the new way to run SQL queries on structured, distributed data
    • Firebase real time database and JSON
    • JSON objects
    • NoSQL databases like MongoDB

    SQL Security
    Cross Site Scripting and SQL Injection
    If allowed to enter special characters in input boxes and forms on a website, hackers may use code to run SQL queries against your database and get data illegally about your website. Many websites do not allow special characters, such as yelp. Some websites stringify the user input before processing it on the server so special characters are turned into strings so to reduce security risk. 

    Saturday, August 4, 2018

    3D Printing Basics 101

    Learn how to 3D Print with Shapeways - Getting Started with 3D Printing

    Take a 3D printing class with shapeways - a famous European printing house

    My personal favorite app to get started is TinkerCAD. You don't need to know 3D modeling to get started.

    Getting Started with 3rd Party Printing

    Here are just a few of the ways our 3D tools make it easy to 3D print with Shapeways:

    1. Check to make sure your design is ready for 3D printing
    2. Reinforce designs that are too thin
    3. Identify loose shells in a 3D scan
    4. Save on labor cost by adding a sinter shell container to multi-part designs
    5. Get feedback from our engineers if we're unable to manufacture your design
    Note shapeways mail from Europe. 

    Useful Apps

    • 123D Scan - an app that can scan real world object into 3D object
    • Shapeways 3D printing model checking tool

    Friday, August 3, 2018

    Android Basics - Views and ViewGroups

    Common views

    TextView, ImageView, ButtonView

    Nested View Groups

    Putting views inside other views. Nesting can be costly and get expensive if there are too many layers of nesting. 

    Best practice using Android Views

    • The view that contains all the views is the root view. 
    • Can organize material design cards into view groups, the button, icon and image inside the card are all nested views. 
    • The linearlayout horizontal and vertical orientations are extremely important.
    • If the elements are not horizontally or vertically spread out, relative layout may be better.
    • Draw a view hierarchy diagram to organize views
    • Indent children views
    • Set layout_width, layout_height dynamically using match_parent or wrap_content

    Thursday, August 2, 2018

    Android ImageView with Drawable images

    The goal is for mobile developers to load images onto mobile applications when limited memory is available.

    Android drawable images @drawable/my_img can be set as the source of an ImageView. Image file extension is optional. Drawable refers to the fact that the image can be drawn on the screen. Android manage all drawables in a res/drawable directory.

    Drawable supports mainly bitmap format including .jpg, .png, .gif. The unit element for these images is a pixel.

    Density independent pixels (DIP) allows ImageView to scale and resize across screen sizes and pixel densities - across the wide variety of Android devices. Specifying button size using dp instead of px make sure the button is still reasonably sized and clickable on high resolution high density screens (high number of dots or pixels per inch).

    Best practice to keep file size small is to include different image sizes for handling different dip's. Android does this automatically and load the corresponding dip drawable assets into the right folder: hdpi, mdpi, xhdpi, xxhdpi.

    Developers also use ImageMagik to compress photos and Android Drawable Importer to convert images to drawable

    Bash - Command Line productivity for developers

    Bash can improve developer productivity. It is available on Mac via terminals. Developers can use bash to write build scripts, enhance dev productivity, use curl to visit and process websites, interact with file systems, modify files, pipe outputs into files.
    • ~ current directory
    • pwd command to show current working directory
    • cd change current directory command
    • ls list files commands
    • ls -l list file with long flag to display detailed info on access, directory, owner, date, file name
    • ls -a list hidden file command
    • . current working directory
    • .. parent working directory
    • cd .. to go up a directory
    • Vim is a text editor in bash

    More reading

    Machine Learning SVM

    SVM can use other functions to make data linearly separable. SVM can give non linear, intricate decision boundaries. SVM Decision Boundary is a straight line for linear SVM.  Apply linear SVM. If it has 0% error, your data is linearly separable.

    c parameter SVM controlls trade off between smooth decision boundary and classifying training points correctly (may not generalize well, get a smooth boundary or get more points classified correctly). Effects of C especially obvious in the RVF kernel. A large c means get more training points correctly. Larger c --> more intricate boundaries

    Gamma Parameter
    Gamma defines how far the influence of a single training example reaches. If gamma has a low value each pointer has a far reach, if gamma has a high value each point has a closer reach.  A high gamma value will make decision boundaries pay close attention to those points that are close, but ignore those that are far. High value of gamma could mean a very wiggly decision boundary.

    A point close to the frontier can really have a lot of weight and pull the frontier close to itself. Versus a low gamma, means more points will have weights of influence on the frontier, so the frontier end up being smoother.

    svm kernel

    Use SVM for Stock finance

    React UI, UI UX, Reactstrap React Bootstrap

    React UI MATERIAL  Install yarn add @material-ui/icons Reactstrap FORMS. Controlled Forms. Uncontrolled Forms.  Columns, grid