Gang of Four design patterns

tutorials:


https://www.tutorialspoint.com/design_pattern/design_pattern_tutorial.pdf


http://edeleastar.github.io/design-patterns/topic00/pdf/c-logica-gof-catalogue.pdf

book:

http://www.uml.org.cn/c++/pdf/DesignPatterns.pdf



http://www.cesarkallas.net/arquivos/livros/informatica/Gang%20Of%20Four%20-%20Design%20Patterns,%20Elements%20Of%20Reusable%20Object%20Oriented%20Software%20-%20Addison%20Wesley%20-%20Site%2051.pdf

Some computer books for general programming design

Some computer books for general programming design:

1. Design Patterns: Elements of Reusable Object-Oriented Software

2. Head First Design Patterns 

3. Clean Code: A Handbook of Agile Software Craftsmanship

4. The art of unix programming.
5. The Art of Computer Programming
6. Programming: Principles and Practice Using C++  
7. c++ Primer 
8. Introduction to Algorithms 

Boto3 check if a s3 folder exists

https://github.com/boto/boto3/issues/134


import boto3
import botocore

client = boto3.client('s3')
result = client.list_objects(Bucket="spark", Prefix="temp/temp2/file3" )

exists=False
if result:
    exists=True

print exists


https://github.com/boto/botocore/issues/680

Install boto3 on python ubuntu

Install boto3 on python ubuntu command:


sudo python -m pip install boto3

Python argparse article

Python argparse article:


https://pymotw.com/3/argparse/

Another useful file.

Another useful file.

https://github.com/chriskiehl/Gooey/blob/master/gooey/python_bindings/config_generator.py

Python arguments, command

Python arguments, command

https://gist.github.com/olooney/8155400

Python positional arguments in chinese

Python positional arguments in chinese



https://docs.python.org.tw/3/howto/argparse.html


http://python.usyiyi.cn/python_278/library/argparse.html

Positional arguments, python

Positional arguments, python:

https://docs.python.org/2/howto/argparse.html

Python positional arguments.

Python positional arguments.

http://stackoverflow.com/questions/6892036/should-i-also-parse-mandatory-arguments-with-getopt

Python *args and **kwargs

Python *args and **kwargs :


https://pythontips.com/2013/08/04/args-and-kwargs-in-python-explained/

python argparse document

python argparse document

https://dmorgan.info/posts/argparse-intro/

Python positional argument

Python positional argument:

https://www.quora.com/What-is-a-positional-argument-in-Python-programming

Python, arguments, options argparse

Python command line, arguments, options, argparse, docs

https://pymotw.com/2/argparse/


https://docs.python.org/2/library/argparse.html


https://docs.python.org/3/library/optparse.html


getopt

https://docs.python.org/2/library/getopt.html


https://pymotw.com/2/getopt/




Design pattern: 


https://softwareengineering.stackexchange.com/questions/307467/what-are-good-habits-for-designing-command-line-arguments

http://stackoverflow.com/questions/54421/what-is-the-design-pattern-for-processing-command-line-arguments

What to learn for JAVA,

j2ee/spring

A good python book

A good python book

Python Essential Reference

BlueJ, a free java development Environment

BlueJ, a free java development Environment :

https://www.bluej.org/

build command line application with click

build command line application with click:

https://www.youtube.com/watch?v=kNke39OZ2k0

Check if an amazon s3 path exists.

Check if an amazon s3 path exists.


http://bigdatatech.taleia.software/2015/12/21/check-if-exists-a-amazon-s3-path-from-apache-spark/

How to install scala 2.13.0

How to install scala 2.13.0


Versions:


https://www.scala-lang.org/download/2.13.0-M1.html

sudo apt-get remove scala-library scala
wget http://www.scala-lang.org/files/archive/scala-2.13.0-M1.deb
sudo dpkg -i scala-2.13.0-M1.deb
sudo apt-get update
sudo apt-get install scala

List, or Array, or RDD can not be used as data type solely in class on scala

For example, such program will have error, "type List takes Type parameters".


import java.io._ class
class Point(val xc: List, val yc: List)
 { var x: List= xc var y: List = yc
 def move()
{ val result=x.intersect(y)
 println ("Length of intersection" + result.length);
 } }
object Demo { def main(args: Array[String])
{ val pt = new Point(List("a","u","r"),List("a","q","r"));
 pt.move();
 }
}

You need to write something like:
import java.io._ class
class Point(val xc: List[String], val yc: List[String])
 { var x: List[String]= xc var y: List[String]= yc
 def move()
{ val result=x.intersect(y)
 println ("Length of intersection" + result.length);
 } }
object Demo { def main(args: Array[String])
{ val pt = new Point(List("a","u","r"),List("a","q","r"));
 pt.move();
 }
}