101companies

Theme:

Python potpourri

Headline

Contributions achieving basic coverage of Language:Python

Description

This theme is under construction.

Direction

Relationships

TODO: Perhaps, some of the implementations could be claimed to be similar to what's going on for other languages.

Headline

A basic Python 3-based implementation

Motivation

Python is a dynamically typed scripting language, mainly focussed on OO-programming but nonetheless offering some tools to also provide basic functional programming capabilities. Python also prides itself on it's "Batteries included" philosophy which means that the language's standard library shouldcover all possible basic use cases of the language. This implementation takes the basic OO approach, implementing Company, Dept and Employee as classes, though due to python's dynamic approach, no inheritance hierarchy is needed (we could do this using dictionaries and classes in fact aren't that much more). Using Python's Pickle serialization module, the whole model can be serialized without further adaptation. The model implements structural equality, but only for the purpose of unit testing serialization.

Architecture

All classes and methods are contained in Company.py. Tests are in CompanyTest.py. Serialization is implemented by the pickle module.

Usage

Make sure to grab Python 3 from python.org, then from the project directory execute 

 python3 CompanyTest.py -v

to run the test cases

Contribution:

pyjson

Headline

Processing Language:JSON-based data in Language:Python

Motivation

This is a very basic implementation which shows to process company data, externally represented in Language:JSON, can be processed with basic idioms of Language:Python. The JSON input is represented in memory as a hierarchically nested dictionary. Hence, all processing depends on recursive loops over the dictionary.

Architecture

There are modules for the basic features.

The sample company is available as a JSON file "input.json".

Usage

Tested with Python 2.7.3.

There is Makefile that automates a test case; see the "test target".

All steps could as well be executed just on the command line. 

./total.py input.json
326927
./cut.py input.json output.json
./total.py output.json
163462

Language:

Python

Contribution:

pyjamas

Headline

Web programming in Language:Python with Technology:Pyjamas

Motivation

Technology:Pyjamas offers the possibility to generate pure Language:JavaScript-Code out of Language:Python source code. One advantage of pyjamas is, that it is very simple to understand. Apart from that, there is no need for complicated Language:HTML or JavaScript programming. Technology:Pyjamas is combined with Language:CSS. It also can be considered as a "spin off" of Technology:GWT.

Illustration

Although pyjamas demands no specific architecture, the main parts of the application are located in a simple Language:Python file this!!101Companies.py. Nevertheless, we have devided the code into two concerns encapsulated into different classes. One class contains the GUI, another class contains the company data and manages the major functionalities of the app. There are further classes for each company, department and employee. The complete Python code illustrated in this section is translated directly to Language:JavaScript.

GUI implementation

The GUI is implemented with the help of pre defined Technology:Pyjamas classes. There is a grid with all necessary components like labels, textfields, listboxes and buttons. The following method of the class 

101CompaniesAppGUI
shows the initialization of the employee part of the GUI: 

# initializes the GUI for the employee view
def initEmployeeGUI(self):
	self.grid.clear()
	self.grid.resize(4, 3)
		
	# row 1
	self.grid.setWidget(0, 0, Label("Name:"))	# column 1 = name
	self.grid.setWidget(1, 0, Label("Address:"))	# column 2 = address
	self.grid.setWidget(2, 0, Label("Salary:"))	# column 3 = salary
	
	# row 2
	self.grid.setWidget(0, 1, self.name)
	self.grid.setWidget(1, 1, self.address)
	self.grid.setWidget(2, 1, self.total)
		
	# row 3
	self.grid.setWidget(0, 2, self.save)
	self.grid.setWidget(2, 2, self.cut)
	self.grid.setWidget(3, 2, self.back)

	# initialize content for current employee
	self.name.setText(self.current.name)
	self.address.setText(self.current.address)
	self.total.setText(self.current.salary)

The three textfields 

self.name
, 
self.address
and 
self.total
and the buttons 
self.save
, 
self.cut
and 
self.back
are initialized in the constructor of the class 
101CompaniesAppGUI
. The 
self
parameter represents the current instance of the class.

Feature implementation

There is only one handler for each button located in the class 

101CompaniesAppGUI
. The handler is implemented by the function 
onClick
. It contains a control structure, which determines the clicked button: 

def onClick(self, sender):
	self.errors.clear()
	if sender == self.cut:
		self.current.cut()
		self.total.setText(self.current.total())
	else if sender == ...

In case of cut, this method cuts the current entity and refreshes the the total textfield. Every class, be it the company, department or employee, implements such a cut method. In case of employee, the specific implementation looks like: 

class Employee:
	...

	def cut(self):
	self.salary = self.salary / 2

	...

Architecture

There are three files, which are not generated:

The file 101Companies.py is divided into three parts:
  • The Feature:Hierarchical company and most of the Feature:Editing is provided by the classes company, department and employee.
  • The GUI is provided by the class 101CompaniesAppGUI.
  • The company initialization and the low-level management of the departments and employees is provided by the class 101CompaniesApp.

Usage

If you only want to watch the Language:HTML/JavaScript-result of the compile process, please:

Technology:

Pyjamas

Intent

A Language:Python-Web-application framework for Language:JavaScript-web applications

Description

Pyjamas provides a Language:Python-to-Language:JavaScript compiler, and many other components including Ajax and a widget-set library. It is based on the idea of the Technology:GWT, which is creating JavaScript web applications without programming JavaScript code <cite>Pyjamas2012official</cite>.

Languages

Technologies