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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3
votes
3answers
120 views

How to write tests for function that depends on a config file?

I have a function that uses information from a config file. How do I test the function? Ideally, I'd want to inject my own version of the config file and test from there, but I'm not using dependency ...
0
votes
1answer
53 views

Is it OK to use name like `CLASS_CONSTANT` for class constant variables according to PEPs? [python]

On the code I'm viewing, I saw a class like this: class User(ModelBase): """# User: docstring""" COMBAT_RANK_KEY_PREFIX = 'combat_rank' LEVEL_RANK_KEY_PREFIX = 'level_rank' ...
4
votes
1answer
887 views

Should I avoid using style like `for k, v in dict_sample.items()`?

Today I was viewing my colleague's code and I saw a function like this: def manager_skill_tree_func(*args, **kwargs): """# manage_skill_tree: Initialize the manage skill tree """ ...
2
votes
0answers
55 views

Method object creation in Python data model

I've been reading the article on the data model of Python on its Reference website, and have been confused about this part: When the attribute is a user-defined method object, a new method ...
1
vote
2answers
145 views

Efficient datastructure to create size-limited dictionary

I need a class that acts like a dictionary but will constrain the total number of key/value pairs it contains. For instance, let's say the maximum number of entries is 1000 and the class already ...
0
votes
1answer
124 views

Does the phrase “range for R1-1 through R10H” actually have an agreed-upon meaning?

I was recently sent a code test by a potential employer to complete on my own time. The first question has to do with identifying whether a given zoning code falls within a range of codes. I'm not ...
1
vote
0answers
54 views

Code structure with MongoDB in python

I am new to MongoDB and python. I know how to make basic use of pymongo in order to manipulate documents. I am having trouble finding how to create some structure or governance in what gets inside ...
0
votes
2answers
68 views

How do I find out what type of exception I am supposed to raise?

I suppose this question is valid for any programming language that can handle (or at least throw) an exception. However I will stick to Python as an example. The top 2 answers to the following ...
0
votes
0answers
77 views

Algorithm for the Simplication and Evaluation of Equations

As a new programmer messing around in python, I've been playing about with writing small programs which can calculate some of the stuff I did in maths at school. I've been trying to think of a way ...
1
vote
0answers
172 views

How to Use Python as a “Macro” runner for a C# Application

I am working on an application that the user may wish to automate some features of (but we don't know what at the moment) I would like to provide them some kind of scripting interface so they can play ...
2
votes
2answers
216 views

Don't repeat yourself vs do only one thing in a method

I am currently writing some test cases in python. I often end up calling the same two or three lines of code at the start of a test case in order to get the program I am testing going. For example: ...
3
votes
3answers
188 views

closure property of datatype “tuple” in python

From this link, below is the slide that I would like to understand: The Closure Property of Data Types A method for combining data values satisfies the closure property if: The result of ...
1
vote
1answer
103 views

adding the digits of a number

I am trying to write a program that asks the user for a decimal number and then calculates the sum of its digits. for example if the number is 123.25 then the sum will be 1+2+3+2+5=13. I decided to ...
-4
votes
1answer
89 views

Understanding If Statement Syntax in Python [closed]

I've recently started learning python, I'm using Python 3.4. I'm trying to understand If-Else statement syntax x=2 if x: print(x) But I'm always encountering this Error IndentationError: ...
4
votes
1answer
79 views

When should I subclass an exception in Python?

In my code there are about seven places where I raise an exception. All of these exceptions are treated the same: print an error to log file, return software state to default and exit. During code ...
0
votes
0answers
40 views

python: area mapping using trigonometric circle

I have a car controlled by a raspberry pi, I would like to create maps to each place it visits. The solution I came up with is simple. Lets say you tell the car to go forward and then after 5 minutes ...
4
votes
3answers
165 views

Is it good Python style to write a function that has no effect other than potentially raise exceptions?

Sometimes I find myself writing Python code that looks like this: def check_stuff(param): if condition1(param): return "condition1" # These might be enum values, etc., instead of strings ...
0
votes
0answers
27 views

Strategy for “multi-level equality” test

It is well-known that Lisp supports multi-level equality test. I want to implement similar multi-level equality test on a custom class in Python. I know that I can (and should) override the __eq__, ...
-2
votes
1answer
97 views

Does datetime.fromtimestamp() return a datetime object or a string?

Basically what the title says. This is a more theoretical question than anything, I don't have a specific use for it. I've looked up the documentation and I can't find a definite answer.
0
votes
1answer
179 views

How to structure GUI program with a database

I am fairly experienced with web design and programming, C, C++ and a little java (used it to build some small GUI). I am trying to work with Python, and I am faced with some technical structuring ...
2
votes
2answers
135 views

Technique to synchronize error codes in a same-project-API

In the project I am working right now, we have some python and some C# code. At some point, I call from python a subprocess which starts a C# executable. This C# code returns an error code, which has ...
2
votes
0answers
400 views

How does the Zope Component Architecture (ZCA) relate to Service Component Architecture (SCA)?

I'm very new to the principle of Service Component Architecture and Zope in general, but the more I look, the more ZCA seems to be a good solution for a certain class of problems I often encounter. I ...
0
votes
1answer
77 views

Is it reasonable to use a decorator to instantiate a singleton in Python?

Suppose I have a class like this: class Foo(object): # some code here As it happens, Foo is a singleton. There are numerous ways to write singletons in Python, but most of them don't really ...
1
vote
3answers
113 views

Which part of the code should rewind a file pointer?

If you had a function that took a handler to a file and then performed some actions that moved the pointer, would you expect it to put the pointer back when it was finished? Additionally, would you ...
1
vote
0answers
33 views

Finding the largest bundle of flagged points

I am currently working to develop a program that takes in an array of 4 columns and around 200,000 rows. Each column represents x, y, z (coordinates), and a flag denoting whether or not this point is ...
2
votes
1answer
106 views

First stab at python classes… when do I need 'self'?

Could someone look over this and let me know if i've butchered anything. It's just a simple class definition in python, but I don't have any local devs to make sure I'm using the language right. ...
1
vote
2answers
167 views

Should I prefer Python generators to lists?

Python iterators can be very memory efficient. Should I always prefer to use generators instead of just lists? In what situations should I prefer a plain array? For example instead of this: emails = ...
6
votes
3answers
797 views

Can “higher order function” feature allow/maintain abstraction and encapsulation?

Below is the function repeat written using a functional paradigm, such that when called as repeat(square, 2)(5) it will apply the square function 2 times on the number 5, something like ...
2
votes
1answer
109 views

Tree search for path finding - algorithm critiques

So, I'm pretty new to AI in general, and am trying to implement a tree-based search from a textfile input (a maze). An example would be: |||||||||||||||||||||| | || | | | \ | |||||| ...
3
votes
2answers
113 views

What is the relationship between scope and namespaces in Python?

In many resources I found "scope" and "namespaces" are used interchangeably, which seems a bit confusing since they mean different things. Scope defines the region of the code where a name is ...
1
vote
0answers
42 views

Structuring a multi-language project?

Let's say I'm working on a project which involves writing code for multiple devices, each in its own language (in particular, Arduino and Python). I want to contain the entire project in a single ...
1
vote
1answer
187 views

Is circular Dependency Injection a good practice?

I'm trying the Dependency Injection pattern in some new classes, more specifically in a Transaction System and stumbled into a dilemma. I have a Person class with a create_new_transaction method, and ...
-1
votes
1answer
131 views

Execute python code without showing the code

I want to use exec to execute python code (using the byte code, instead of the raw text that python will interpret). It's all for a competition where you can see the code of the other competitors, I ...
-1
votes
1answer
393 views

Python: Faster to use global variable or pass as arguments to a function? [duplicate]

Hey so i was wondering which is the more efficient way, or better practice to do in this situation. 1, def function(): global number number += 2 Or 2, def function(number): return ...
0
votes
2answers
45 views

Iterating a function with a static argument: Global functions + lambdas vs internal function?

I am never sure which of these is better form: Option A def a(x,y): def b(z): return z+y return map(b, x) print a([10,20], 5) Option B def b(z,y): return z+y def a(x,y): return ...
1
vote
0answers
42 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
92 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) ...
5
votes
3answers
437 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 ...
0
votes
1answer
148 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 ...
4
votes
1answer
231 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
vote
1answer
90 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. ...
-2
votes
3answers
125 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. ...
4
votes
1answer
64 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 ...
0
votes
0answers
34 views

moving Data mining model from “lab” to production environment

I am designing the architecture of an analytics system . I have a data mining ensemble model developed in scikit learn . I want to move this to the production environment so the new incoming data can ...
2
votes
1answer
40 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
vote
1answer
64 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
vote
0answers
52 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
348 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
votes
1answer
44 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. ...
1
vote
0answers
52 views

Is there a standard practice on making a modular Python script?

I wrote a Python script for PIA here: pia-auto-login.py However, I need to make it more modular so that it does the OpenVPN changes from this script. Then I want to create two more packages (at ...