Python is a dynamic, high-level language. Its design focuses on clear syntax, an intuitive approach to object-oriented programming, and making the right way to do things obvious. Python supports modules, exceptions, had an extensive standard module library. Python can also be embedded in other ...

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2
votes
2answers
615 views

One boilerplate class or many similar classes?

Lets say I'm trying to model a variety of objects that are virtually identical, the only difference being their class variables. Am I better off creating one boilerplate class and just calling the ...
0
votes
1answer
127 views

Simple unicode application?

I want to create simple language learning applications to help friends in learning languages. A simple Java console application would do the trick, but the Windows console does not seem to handle ...
1
vote
4answers
121 views

Efficient “Object with weights” structure

I need to find an "efficient" data structure / set of algorithms to do the following things: I have a list of objects. I need to assign them weights and later on increase or decrease these weights. ...
3
votes
1answer
162 views

What is the right way to process inconsistent data files?

I'm working at a company that uses Excel files to store product data, specifically, test results from products before they are shipped out. There are a few thousand spreadsheets with anywhere from ...
0
votes
2answers
133 views

At what point should you start putting functions in a new file? [closed]

I'm currently writing a python script. It's currently about 400 lines long, and it seems like it's getting a bit long, as when I'm trying to scroll through it with eclipse it takes a bit to get from ...
1
vote
2answers
584 views

What is the proper name for this design pattern in Python? [closed]

In Python, is the proper name for the PersonXXX class below PersonProxy, PersonInterface, etc? import rest class PersonXXX(object): def __init__(self,db_url): self.resource = ...
7
votes
3answers
316 views

Does it make sense to develop open source python library for database inspection? [closed]

Some time ago I came up with an idea for a library for database inspection. I started developing it and got some very basic functionality, just to check if that's possible. Recently however, I get ...
7
votes
6answers
2k views

Python mutable default argument: Why?

I know that default arguments are created at the function initialisation time and not every time the function is called. See the following code: def ook (item, lst=[]): lst.append(item) ...
4
votes
3answers
841 views

What's the best way to create a static utility class in python? Is using metaclasses code smell?

Ok so I need to create a bunch of utility classes in python. Normally I would just use a simple module for this but I need to be able to inherit in order to share common code between them. The common ...
13
votes
5answers
2k views

Is it a good practice to declare instance variables as None in a class in Python?

Consider the following class: class Person: def __init__(self, name, age): self.name = name self.age = age My coworkers tend to define it like this: class Person: name = ...
3
votes
2answers
210 views

Which programming idiom to choose for this open source library?

I have an interesting question about which programming idiom is easier to use for beginner developers writing concrete file parsing classes. I'm developing an open source library, which one of the ...
1
vote
2answers
172 views

Is creating and writing to one large file faster than creating and writing to many smaller files in Python on Linux?

If using Python on a Linux machine, which of the following would be faster? Why? Creating a file at the very beginning of the program, writing very large amounts of data (text), closing it, then ...
37
votes
2answers
4k views

How do I move away from the “for-loop” school of thought?

This is a rather conceptual question, but I was hoping I could get some good advice on this. A lot of the programming I do is with (NumPy) arrays; I often have to match items in two or more arrays ...
0
votes
3answers
128 views

How to convert this recursive problem to iterative? Line Simplification algorithm fails to run due to Maximum Recursion Depth being hit

I am implementing the Douglas, Peucker's Line Simplification algorithm in Python. I started with this implementation. However, it fails to run in Python due to Maximum Recursion Depth being hit. How ...
4
votes
4answers
847 views

How does Python compile some its code in C?

I read that some constructs of Python are more efficient because they are compiled in C. https://wiki.python.org/moin/PythonSpeed/PerformanceTips Some of the examples used were map() and filter(). I ...
17
votes
9answers
5k views

Why hasn't C# gained much traction within the opensource community? [closed]

I'm not expecting C# to be on par with say Java or Python in the open source community, but it still surprises me just how far behind it is. 'Multi language' open source repos like google code or ...
0
votes
1answer
164 views

Best Practices For Temporary Scripts (Python)

I am running two separate programs which are similar enough that they share a lot of code. I run these programs often and after I evaluate the output. This is a very fluid process and everytime is ...
9
votes
5answers
978 views

Are there technical limitations or language features that prevent my Python script from being as fast as an equivalent C++ program?

I'm a long-time Python user. A few years ago, I started learning C++ to see what it could offer in terms of speed. During this time, I would continue to use Python as a tool for prototyping. This, it ...
3
votes
2answers
131 views

Should I use nested matrices or dictionaries?

As per Should I ask my question about which data structure to use here? I'm asking this here. Hopefully this isn't too implementation specific. I'm currently developing a program that will represent ...
1
vote
3answers
193 views

How do I test my code in Python other than by doing it by hand?

I am used to user testing in Java, and I also manually test each section of code I write, but now, I want to automate it. There is no GUI for this project, so user testing is not required and I can ...
0
votes
1answer
62 views

Where to save something between invocations?

The 2nd time I run this program I'd like it to start in the same HDD location as the previous instance. How should I save, or remember, where I was so the program starts in the same place? I'd like ...
2
votes
1answer
250 views

How do you make decorators as powerful as macros?

Quick background: I am designing a Pythonic language that I want to be as powerful as Lisp while remaining easy to use. And by "powerful", I mean "flexible and expressive". I've just been introduced ...
0
votes
1answer
146 views

Python case statement? [duplicate]

I made a simple Python script that takes user input in order to generate a series of mathematical responses. In one part I did this: while True: And iterated through the loop until I used an if ...
15
votes
10answers
4k views

Why are inheritance and polymorphism so widely used?

The more I learn about different programming paradigms, such as functional programming, the more I begin to question the wisdom of OOP concepts like inheritance and polymorphism. I first learned ...
0
votes
2answers
148 views

How to route messages between clients using a central server in Python

I've got three Raspberry Pis sitting around. I want 2 of them to be able to chat while the 3rd routes the messages (acts as a server between them). The general flow of events should be something like ...
25
votes
6answers
11k views

Programming language usage at Google [closed]

I have heard Google uses Python, Java and C++. But what I don't know is how is each of those programming language is used. I mean what is Python, Java and C++ is used for at Google. Why would they ...
1
vote
1answer
177 views

Is Lambda Still Supported In Python?

Only one or two years ago, I remember reading Python constructs that would be removed from Python -- reduce was one of them -- and other constructs that would be emphasized like comprehensions and ...
4
votes
2answers
300 views

What are the key differences between Java's and Python's OOP support? [closed]

The only language I've ever used is Java. I like it a lot but decided it's time to learn another language :) . I'm interested in learning Python. It seems like a good choice because it's partly ...
0
votes
1answer
111 views

Making a sldprt to PDB file converter?

I wanted to create a parser that can read a solidworks file and turn it into a protein data bank file. This has already been done in a program called DiamondCAD. ...
1
vote
1answer
154 views

Should I separate a web api from the webserver?

Lets say I'm building a site similar to this or Quora (or some arbitrary blog-like site). I need a real-time component that will be using web-sockets/long-polling to notify the user of new posts, ...
3
votes
1answer
277 views

Good practice for returns in Python

I was recently working on some prototype code in Python. The code worked great, then I realized that I needed a little more feedback from one of my functions so I changed the return statement from ...
40
votes
1answer
20k views

Module vs. Package?

Whenever I do from 'x' import 'y' I was wondering which one is considered the 'module' and which is the 'package', and why it isn't the other way around?
10
votes
2answers
239 views

Early attempt to remove Python GIL resulted in bad performance: Why?

This post from Python creator, Guido Van Rossum, mentions an early attempt to remove the GIL from Python: This has been tried before, with disappointing results, which is why I'm reluctant to ...
0
votes
1answer
470 views

Javascript function should call python logic in django web development without additional triiger

I have been trying to solve this problem for sometime now. This is regarding django web development. I have an HTML page which has a Javascript function to upload an image file from the users local ...
-4
votes
2answers
235 views

A newbie in python trying to learn [closed]

Am trying to learn how to program before i go to uni and i stumbled upon a question which i have been unable to do. In the function write code to input two integers m and n and calculate and display ...
3
votes
2answers
481 views

where exactly should python business logic be placed in django

I have just begun to learn Django/Python/Web Development. This problem has been troubling me for a while now. I am creating an application with multiple templates in Django. I have a views.py which ...
0
votes
2answers
288 views

Google App Engine overview

I have gone through many Google App Engine tutorials, and I became quite familiar with how to do basic stuff like implementing a webapp2.RequestHandler, and using ndb.Models to manage your data. Now, ...
3
votes
1answer
79 views

optimize human-readable database with index

i need to store a large amount of data - about 10 million entries of the format unique hash (64 chars), value 1 (5 chars), value 2 (9 chars) i will be reading and deleting (but not updating) this ...
0
votes
0answers
26 views

How to deal with multiple output modes of multiple types?

Note: The business domain being a bit complicated to explain, I replaced the names of actual classes by more illustrative examples. I'm writing an application in which the business layer returns a ...
2
votes
0answers
129 views

The inheritance argument of zope.interface (providedby vs isinstance)

What limitations does inheritance of an interface through an abstract base class present that are addressed by zope.interface? In the following talk given in 2010 by Jeff Rush about interfaces, at ...
2
votes
2answers
82 views

subclass reference to another subclass

Imagine I have the following code: class A: pass class B(A): pass class C(A): def __init__(self): self.b = B() Is the above code correct in terms of correct inheritance? I ...
0
votes
0answers
32 views

Defining property and find substitution for copy function of python in cython

I want to cythonize a code in python to speed up the code. In the following you can see my attempt to make my python class understandable for cython: import numpy as np cimport numpy as np ctypedef ...
2
votes
1answer
96 views

Python API: Extension Module or Pure Module

We have a C++ application, with C++ interfaces changing regularly during development. We also have a C API which is designed to be stable in spite of such changes; the C API is tighly focused on ...
1
vote
1answer
79 views

Adding new functionality to all of shelve.Shelf's subclasses in Python

In order to avoid the overhead associated with the shelve module's writeback option I'm interested in putting together a shelf class that only accepts hashable values, with hashability being a proxy ...
1
vote
2answers
194 views

Can a version of Python's shelve module that knows when its entries have been modified be written in any programming language?

shelve is a Python module that makes it easy to persist a Python dictionary to disk (under the right conditions). The documentation for shelve gives this example to demonstrate one of the pitfalls of ...
13
votes
5answers
5k views

Is it considered Pythonic to have multiple classes defined in the same file?

In working with python for the first time, I've found that I end up writing multiple classes in the same file, which is opposed to other languages like Java, which uses one file per class. Usually, ...
1
vote
1answer
577 views

scons and python unit tests best practices

I am using scons to build a large project containing a mix of C++ and Python. I would like scons to run Python unit tests either using nose or not. Currently, we have a long list of tests files and ...
0
votes
1answer
144 views

Measuring performance of a network simulator?

I have written a python program to test a new network routing algorithm, that uses a Content Centric Network Approach for handling requests (CCN), where the CCN router keeps 3 data structures: A ...
1
vote
1answer
96 views

Using class like an object in Python

I am learning from Learn Python the hard way where I have come across a study drill where they want to know that whether a class can be used like an object. As I have experimented: class A(object): ...
1
vote
2answers
154 views

How would I change the precision of a variable in Python?

I'm working on a 2D-physics engine, and I need a certain variable to be precise only to the hundredths. Are there any methods for basically shaving off all of that unneeded precision? I have tried ...