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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0answers
103 views

Need to add websocket support to a single page that's running a wsgi service

Current setup. I have a legacy ERP system (Thoroughbred) and i then have several in house applications (CRM, WMS) and a website that interact with it via an xml server and straight ODBC connections. ...
0
votes
2answers
105 views

Empty except block vs. huge except block

Which of these is easier to read? An empty except block: try: foo = do_foo() except FooError: pass # see below else: return do_bar(foo) # Recover from the FooError (long, complicated) ...
9
votes
4answers
674 views

Why do python generators and functions share the “def” keyword?

Consider the following: def some_function(): return 1 def some_generator(): yield 1 In the code above, some_function is a function, while some_generator is a generator. They look quite ...
1
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1answer
316 views

Best strategy for converting change in longitude and latitude to north, south, east, west in degrees

This is not a class assignment but a conceptual question I'm struggling with for a personal project. I need to convert a large paired group of long and lat coordinate values that show a ...
5
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1answer
328 views

Any reasons NOT to write self testing Python code?

Whilst writing tests I was giving considerable thought to the question of how to ensure I have tests for every class in my application. It occurred to me that maybe I should just put the test code ...
1
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1answer
151 views

Allow user to enter DSL, rules or code?

I have a python library that allows me to define rules by chaining inputs and outputs of functions ( producer(grep(count( [print(),log() ] ))) This functions define a pipeline from left to right. ...
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votes
3answers
217 views

How to manage a large list of distinct numbers

I have a list of around 2 billion distinct numbers stored in memory for some computation. Currently, every time I need to add a new entry I have to search the entire list for a potential duplicate. ...
5
votes
1answer
86 views

Should I use exceptions to control the range of parameters in Python?

For example for the following method signature: def genClusters(n_clusters, n_nodes, cluster_distribution): n_clusters should be an integer of more than 1. n_nodes should be an integer of more ...
3
votes
1answer
54 views

Is there a standard project metadata / dependency file for Python?

In my Node.JS projects, I save my project metadata into package.json: dependencies, version number, author, description, and so on. This makes it so anyone can clone my project and run npm install to ...
1
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1answer
158 views

Persist data downloaded by Celery workers

I'm working in a tool that downloads tweets from Twitter to process them later. For this purpose I'm using Celery with RabbitMQ, sending task with the keywords that must be tracked by the workers. My ...
1
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0answers
76 views

Improve communication between controller and trackers in a Twitter fetcher tool using RabbitMQ or Apache Flume

I've been working for a time with some researches developing a tool to fetch tweets from Twitter and process them in some way. The first prototype "worked" but became a pain as we used sockets to ...
2
votes
3answers
454 views

Multiple users using the same script for their websites

I'm working on a project, I have a question regarding the architecture: Say I have a many python scripts on my server and there's main.py which contains all the classes. And there's a script called ...
0
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1answer
58 views

Should I have all models done before I syncdb?

I'm not sure if I want to add more attributes to my models or create another model. I've coded up to the point where I need to syncdb to start using some data in the site, but I'm hesitant to do it. ...
0
votes
2answers
234 views

Using a bytearray rather than a string to store password in memory

Using a bytearray datatype to store a password (in memory) has an advantage over using a string datatype for a password in that a bytearray is mutable and can be overwritten with 0x00 values when the ...
0
votes
1answer
2k views

Facing MemoryError in Python

I wrote a program to find prime factors of a number. When I give a large number(600851475143) as input, MemoryError pops up. Below is the code: def fact(a): factors = [] for i in ...
8
votes
4answers
2k views

why empty function are needed

I started learning python and I am wondering why empty function are needed in a programming language e.g. in python: def empty_func(): pass even in shell scripts empty function empty functions ...
117
votes
15answers
18k views

Is it always a best practice to write a function for anything that needs to repeat twice?

Myself, I can't wait to write a function when I need to do something more than twice. But when it comes to things that only appear twice, it's a bit more tricky. For code that needs more than two ...
1
vote
1answer
593 views

Repeating groups of arguments with argparse

Let's say that I want to enter info about multiple users from the command line AND that each user has multiple data associated with it. Is it possible (syntactically permissible) to use argparse to ...
1
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1answer
276 views

How would a modern website like Reddit divide up its website into Django apps? [closed]

Django uses apps to divide projects into manageable and reusable chunks. All examples in tutorials use polls or articles in unrelatable circumstances. In a modern example like Reddit (or even Amazon ...
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1answer
111 views

Send Emails Via APIs or Code?

I am Using SendGrid to Send Emails to my Users. There are two ways to send emails via SendGrid. 1 - Via APIs 2 - Via Program/Code I want to know which one is More Secure and efficient way. I am ...
0
votes
4answers
506 views

Identifying user of a webapp

For a small webapp I want to be able to identify a user. The issue is, if the user cheats in some manner, I want to be able to forbid him the usage of my application. I already have done extensive ...
11
votes
2answers
4k views

How to efficiently store big time series data?

I need to store and to be able to query some very large amounts time series data. Properties of the data are as follows: number of series : around 12.000 (twelve thousand) number of data points, ...
1
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1answer
334 views

Splitting single Class into multiple Classes

I am writing automated test scripts with Selenium Webdriver (Python) and I try to follow the correct programming practices, specifically the Object Oriented methodologies, where possible. At the ...
1
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0answers
2k views

Best practices to parse a log file using Python

I'm writing a Python tool to parse a log file from game server. The log file is of format: ms:classname::id::method::arg1::arg2.... There are a lot of classes, and a lot of methods for each class, ...
7
votes
2answers
261 views

Version control for code that contains student exercises

I have a fairly substantial Python project that I have developed as an educational endeavor. The version of the code that shall be given to students has exercises throughout, in the form of code that ...
1
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3answers
97 views

Using higher order functions to apply m out of M filter's and then transform data of size n?

Total no: of filters possible is M . User can select m filters where m <= M . A typical example is files from a folder , he could say modified between so and so date , start with so and so and so ...
1
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1answer
525 views

Does dynamically generating classes in python affect readability/performance?

I have a set of classes that represent different objects (tables in a database): class ObjA: # some class specific attributes and methods def refresh(self): # implementation ...
4
votes
3answers
3k views

How to use multiple programming languages together in the same program? [closed]

Such a simple question, but I have not found a reasonable answer to this. I currently program in Python, an interpreted language. I always hear of people using multiple languages in the same program? ...
1
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1answer
362 views

From which point does it become dangerous to keep going as the sole developer on a project? [duplicate]

I'm working at a company where the management wants to capitalise on consulting experience to offer quality software to their (already existing) customers, and expand from that to become one day ...
0
votes
2answers
163 views

How early does a hashable type need to become immutable?

Suppose I have a class that looks vaguely like this: class Foo(object): _value = None # XXX: see below def __init__(self, value): self._value = value @property def ...
2
votes
3answers
281 views

How do I deal with imported modules in GPL?

I wish to release a non-commercial python application under GPL3 in both source and (PyInstaller) executable form. I'm struggling to find a consistent answer to the problem of imported modules. Can I ...
4
votes
1answer
115 views

How should I represent composeable, associative computations to be repeatedly applied to units of data?

Spoiler My question is the following: Are there any design patterns for representing chainable functions that are for the problem described below? High-Level Decription of the Process I'm ...
0
votes
2answers
133 views

Is it ok to access private members while doing same class comparison?

I am writing a class which basically is a wrapper around a dictionary with some extra functionality. This dictionary is stored as protected member _store. Now I am writing a __eq__ method to compare ...
0
votes
1answer
70 views

Why do objects created with no assignment not generate a syntax error in Python?

While working on a Python project, I realized that during my editing I had left a string floating around in the middle of my code and it didn't generate an error. For example, these few lines execute ...
0
votes
1answer
245 views

Python recipe question: Use of **kwds instead of specific named argument in itertools recipe [closed]

The function definition below comes from the itertools recipes page (https://docs.python.org/2/library/itertools.html#recipes). def random_product(*args, **kwds): "Random selection from ...
3
votes
1answer
168 views

Python Open Source Development

I am looking to contribute to some Python projects on Github, and I am looking for a bit of clarification on the mechanics of doing this effectively. As I understand it, the typical workflow is as ...
0
votes
1answer
57 views

How can I determine which version of Python introduced a particular module to the std lib? [closed]

Is there a single timeline-style resource available showing the history of the modules available in different versions of Python? I'd like to, for instance, easily determine which version of Python ...
4
votes
2answers
257 views

Changing method signature while keeping backwards compatibility

I've inherited an API to maintain. Users can pass a callback function to the class which gets called on some event. The callback function is currently passed in a single argument. I need to change ...
1
vote
3answers
3k views

What can C++ do that Python cannot? [closed]

I was reading this post: http://www.quora.com/What-are-the-advantages-of-Python-over-C++ And I am wondering the converse of this question: what can C++ do that Python cannot? For example, in the ...
0
votes
1answer
123 views

Should I use a class as a wrapper?

Lets say I have a class representing a chemical compound class Compound(networkx.Graph): def __init__(self): super(Compound, self).__init__() And lets say that I want to add some ...
3
votes
4answers
1k views

What argument passing mechanism does python use, and where is this officially documented?

As far as I am aware, python is generally referred to as 'call-by-sharing', but does it implement this with call-by-value (like Java) or call-by-reference? or something else? I would appreciate if ...
3
votes
6answers
729 views

Why is python treated as a interpreted language when it has a compiling stage? [closed]

Why is that python is treated as only an interpreted language when there is in fact a compiling stage where the code we write gets converted into byte code(.pyc), which is later interpreted by the ...
6
votes
0answers
210 views

Which languages have the best support for stackful coroutines? [closed]

Various languages support (some flavor of) coroutines. One way to discriminate coroutines is whether they are stackful or not (terminology based on Ana Lucia de Moura; Roberto Ierusalimschy (2004). ...
0
votes
1answer
54 views

Django Project Logic Solution

I'm starting to develop my first webapp, and I'm using django. Before anything I'm working on the software logic, how it should work, the links and objects it needs. The problem is: I need the app ...
0
votes
1answer
70 views

how python updates references to variables

For this while loop below. It is clear how the v1,v2,v3 are updated to new data objects based on the equation. But I do not understand how u1,u2,u3 retains the original values of v1,v2,v3.Can someone ...
3
votes
1answer
943 views

how to test a generator with unittest?

I have programmed a small iterator in Python: class anything(): def __init__(self): self.i=1 def __iter__(self): return self def next(self): if self.i>100: ...
3
votes
2answers
229 views

Naming self or this something else, a good idea?

I'm finding that my code becomes more readable when I make a local reference to this/self, and/or call it something that makes sense in the context. "self" or "this" doesn't really indicate what kind ...
1
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2answers
228 views

Python: Object initialised inside a Class?

Is possible and, if so, common practice to initialize an object inside a class in Python? self.field = Class()
5
votes
2answers
2k views

Every function is a closure?

Wikipedia says, that closure - is a function, which has an access to variables, declared outside of the function. There is even an example: function startAt(x) function incrementBy(y) ...
0
votes
1answer
97 views

Handling the process of large-scale lists [closed]

What are the efficient ways to process huge lists (+10 millions), and things to consider while manipulating huge lists. First question, when should I use recursion, and when I shouldn't. In both ...