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Wednesday, July 10, 2019

Python - Creating Module Packages


Intent

Beyond importing someone else's packages, sometimes it helps to make your own. This will assist in the understanding of how to do so.

I. It helps to have the pep8 compliance package to test.

py -3 -m pip install pytest
py -3 -m pip install pytest-pep8

Next step, make sure your module is pip complaint


  1. cd to your module and run…
  2. py.test --pep8 vsearch.py

Common Errors Found

  1. Not having two blank lines between each function
  2. Not having a white space following a colon
  3. Using tabs to indent. It prefers 4     blank   manual    lines

Note the ^ will mark where in the code it believes things are out of compliance.




II. Next a setup.py and a README.txt file are required

 

Creating setup.py

 

Textbook example:
from setuptools import setup

setup(name='vsearch', version='1.01', description='The Head First Python Search Tools', author='HF Python 2e', author_email='hfpy2e@gmail.com', url='headfirstlabs.com', py_modules=['vsearch'],)

Creating README.txt

Just put in whatever you want. So long as the README exists.

III. Run setup.py as the setup distribution

In the command line run as follows: 

py -3 setup.py sdist

IV. Install your new module from within it's distribution



Example:

py -3 -m pip install [moduleName]-1.0.zip

V. Now you can run your module. Don't forget to run it as something, or you'll have to call it by what it is. Have fun! :)

Python Basic Data Structures and Common Commands Cheatsheet


Lists
[]
list
append, extend, pop, index
Tuples (immutable)
() or {},
tuple

Sets
{'',}


Dictionary
{}
dict


List | Common Commands:

Append | For adding a single element. If you give it a list, it'll add a list of a list
Extend | for merging a lot of elements
Clear | for clearing the element
Index | for searching the position of an item, first occurrence.
Remove | for removing a specific item, first occurrence
pop | for removing a single item from at a INDEX position (AND returning it if need be). 
Copy | For creating a new object. Anyway else will just reference the old object
Reverse | Flips things over
Count | Built in Frequency Counter


Examples




Iterating in Python Sampler


for i in [1, 2, 3]:
print (i)

for ch in "Yay!":
print(ch)

for num in range(5):
print('David is good at this!')

help(range)


phrase="Don't Panic!"

All the Letters

phrase

Every Third Letter up to index location 10

phrase[0:10:3]

All letters up to but not including the 10th
phrase[:10]

Only the first three letters
phrase[3:]

Every Second Letter
phrase[::2]

How to count backwards 1
backwords = phrase[::-1}
''.join(backwords)

>>> phrase[::-1]
"!cinap t'noD"

How to count backwards 2
>>> phrase = "The Sky is Blue"
>>> words = phrase.split(' ')
>>> words
['The', 'Sky', 'is', 'Blue']
>>> words[::-1]
['Blue', 'is', 'Sky', 'The']

Sunday, June 2, 2019

Spring Core Containers and Dependency Injection

Java classes should be as independent as possible from each other.


  • To decouple classes from one another, dependencies should be injected through Constructors and Setters.
  • Classes should not configure themselves. IoC uses dependency injection to: 
    • Configure a class correctlyi from outside the class
    • Wire services or components.
  • Piecing together all the beans in the Spring Container is called Wiring.
    • This can most commonly be don through xml.
    • Various BeanFactories and ApplicationContext objects that support wiring include:
      • XMLBeanFactory
      • ClassPathXMLApplicationContext
      • FileSystemXMLApplicationContext
      • XMLWebApplicationContext

Spring Fundamentals

Originally developed to fight against low level maintenance, Spring framework functionality can be used in any JavaEE server and most of it is also adaptable to non-manage frameworks.

Most JavaEE applications are complex and require a lot of effort to develop.

Spring's BeanFactory enables configuration options from XML by providing dependencies when required, automatically.

Spring is composed of 7 key components. These modules can be chosen freely as needed.

  1. Spring Coreseparates configuration from dependencies
    • Prime Components: BeanFactory; Application contexts.
    • Bean Factory: Provides support for dependency injection.
    • Application Contexts: provides application framework services.
  2. Spring Context
    • A configuration file that provides contextual information to the Spring Framework. JNDI, EJB, email, scheduling and internalization services.
  3. Spring AOP
    • Integrates Aspect Oriented Programming through its configuration management feature, providing transaction management services for objects in any Spring-based application.
  4. Spring DAO
    • Data Access Object abstraction layer offers a meaningful hierarchy for the managing of exceptions and error messages. This greatly reduces the amount of code you need to write, such as opening and closing connections.
  5. Spring ORM
    • Object Relational Map -Object oriented programs and relational databases tend to speak completely different languages. This bridges that gap. This provides support to several ORM solutions, including Hibernate, JDO, JPA, and others.
  6. Spring Web Module
    • Builds on top of the application context module, to provide contexts for Web-based applications. The Web module
  7. Spring MVC
    • A full featured MVC implementation for building Web-applications. Highly configurable via strategy interfaces. It accommodates numerous view technologies including JSP, Velocity, Tile, and so on.

Tuesday, May 28, 2019

Git Tips

Git can be confusing. You try cloning someone else's repo and it doesn't work. Or you = try to move branches…its all kinda counter intuitive. Unless I write down some important lessons learned right here.


Add Collaborators

  • The master of the repository has to add users to allow them to interact with stuff. I'm yet to master the security features, as I accidentally overrode the master branch today (DAMMIT)
  • Here is the link to the guide used.


Who are you?

To collaborate you must set your glob= al user variables under config.
  • git config --global user.= name
  • git config --global user.email
  1. git con= fig --global core.editor [vi | cat | w]
    Change = the main editor to vi or cat, etc

Git Branch =Making New Backup Folders

I like to think of branches as different backup folders. As one familiar with most DOS commands, what is the equivalent of making a new folder (mkdir) and cding into it? Let along listing (ls) them?

mkdir
git branch [branchName]
ls
git branch -= a
cd
git checkout [branchName]

  1. git branch -a =3D=3D ls [= your branches] 
  2. git branch [branchName]= =3D=3D create a new branch
  3. git checkout [branchNam= e] =3D=3D cd to your brannch


Git Add = Prepare to Save.

    1.  You need to use -a or . from within t= he same folder as the .gitignore command for this to work.

Git Commit = Save Local Copy, but you need to have a message (apparently)


  • Commit doesn't like you unless you add in -m after calling the command. So you must either vi or cat or something else. As long as there is a message.

After Cloning, you have to work within the folder itself

  • No amount of trying to add the folder I cloned seemed to cause the thing to be sta= ged. You have to work where the .gitignore file is.


Resizing Disks in Virtual Box

Use this guide




Quick Tips:

  1. This will only work on Dynamically Allocated Disks. It will NOT work on fixed disks.
  2. Put .\ in front of the command vboxmanage.exe

Sample Command:

.\vboxmanage.exe modifymed= ium "C:\Users\David\VirtualBox VMs\Ubuntu2019\VirtSSD.vhd" --resize 3= 0999