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Data Structures and Algorithms with Object-Oriented Design Patterns in Python

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Making Games with Python and Pygame Book Description This is a programming book that covers the Pygame game library for the Python programming language. Each chapter gives you the complete source code for a new game and teaches the programming concepts from these examples. About the Authors Albert Sweigart (but you can call him Al), is a software developer in San Francisco, California who enjoys bicycling, volunteering, haunting coffee shops, and making useful software.

Design Patterns | Object Oriented Design More about interactive graphs using Python, d3.js, R, shiny, IPython, vincent, d3py, python-nvd3 I recently found this url The Big List of D3.js Examples. As d3.js is getting popular - their website is pretty nice -, I was curious if I could easily use it through Python. After a couple of searches (many in fact), I discovered vincent and some others. It ended up doing a quick review. Every script was tested with Python 3. Contents: If you want to easily produce a html file including javascript (to publish it on your website for example), you only need to look at sections Graphs with Python and d3py, Graphs with IPython and nvd3. Use of IPython (qt)console The QtConsole looks like a command line window but is able to display images inline using matplotlib: You can enable it by using the following steps: Install pyqt (only once, Windows users can go there)Go to <Python folder>/Scripts and type ipython3 qtconsoleIn the console, type %matplotlib inline To test it is working, you can type and press enter: %load

Business News & Financial News - The Wall Street Journal - WSJ.c Dijkstra's algorithm The algorithm exists in many variants; Dijkstra's original variant found the shortest path between two nodes,[3] but a more common variant fixes a single node as the "source" node and finds shortest paths from the source to all other nodes in the graph, producing a shortest-path tree. For a given source node in the graph, the algorithm finds the shortest path between that node and every other.[4]:196–206 It can also be used for finding the shortest paths from a single node to a single destination node by stopping the algorithm once the shortest path to the destination node has been determined. For example, if the nodes of the graph represent cities and edge path costs represent driving distances between pairs of cities connected by a direct road, Dijkstra's algorithm can be used to find the shortest route between one city and all other cities. Dijkstra's original algorithm does not use a min-priority queue and runs in time (where is the number of nodes). History[edit] Algorithm[edit] is and

Python The Case for Test-Driven Development By Meghan Blanchette March 28, 2014 Harry Percival, author of Test-Driven Web Development with Python, discusses how he got into TDD, why you should too, and shares some tips. In the podcast above, listen to Harry talk candidly about the types of tests that make sense, … Interface Languages and Feature Discovery By Ben Lorica March 2, 2014 Here are a few more observations based on conversations I had during the just concluded Strata Santa Clara conference. Four short links: 28 February 2014 By Nat Torkington February 28, 2014 Programming Minecraft Pi with Python — an early draft, but shows promise for kids. Four short links: 31 January 2014 By Nat Torkington January 31, 2014 Bolts — Facebook’s library of small, low-level utility classes in iOS and Android. IPython: A unified environment for interactive data analysis By Ben Lorica January 19, 2014 More News – More Answers

Design Patterns In software engineering, a design pattern is a general repeatable solution to a commonly occurring problem in software design. A design pattern isn't a finished design that can be transformed directly into code. It is a description or template for how to solve a problem that can be used in many different situations. Uses of Design Patterns Design patterns can speed up the development process by providing tested, proven development paradigms. Effective software design requires considering issues that may not become visible until later in the implementation. Often, people only understand how to apply certain software design techniques to certain problems. In addition, patterns allow developers to communicate using well-known, well understood names for software interactions. Creational design patterns These design patterns are all about class instantiation. Structural design patterns These design patterns are all about Class and Object composition. Behavioral design patterns Criticism Read next

The Python “with” Statement by Example Python’s with statement was first introduced five years ago, in Python 2.5. It’s handy when you have two related operations which you’d like to execute as a pair, with a block of code in between. The classic example is opening a file, manipulating the file, then closing it: with open('output.txt', 'w') as f: f.write('Hi there!') The above with statement will automatically close the file after the nested block of code. Here’s another example. This code sample uses a Context object (“cairo context”) to draw six rectangles, each with a different rotation. cr.translate(68, 68) for i in xrange(6): cr.save() cr.rotate(2 * math.pi * i / 6) cr.rectangle(-25, -60, 50, 40) cr.stroke() cr.restore() That’s a fairly simple example, but for larger scripts, it can become cumbersome to keep track of which save goes with which restore, and to keep them correctly matched. By themselves, pycairo’s save and restore methods do not support the with statement, so we’ll have to add the support on our own.

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