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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-4
votes
1answer
86 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
74 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
35 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
162 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
25 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
69 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
150 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
127 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
387 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
70 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
111 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
30 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
99 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
162 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 = ...
5
votes
3answers
790 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
102 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
105 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
37 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
165 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
125 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
249 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
44 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
32 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
91 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
421 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
121 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 ...
3
votes
1answer
228 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
87 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
123 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
62 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
33 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
0answers
44 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
39 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
342 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
42 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
47 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 ...
0
votes
1answer
107 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
355 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
331 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 ...
105
votes
15answers
16k views

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

For myself, I can't wait to write a function when I need to do something more than twice. But when it comes to the things that only appear twice, it's a bit more tricky. For code that needs more than ...
1
vote
1answer
139 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
vote
1answer
183 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 ...
-1
votes
1answer
51 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
259 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 ...
7
votes
2answers
488 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
vote
1answer
85 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
vote
0answers
363 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, ...
1
vote
0answers
126 views

Why does this code work? [closed]

I'm taking Udacity's Intro to Computer Science course and one of the quizzes had me create a function that takes in two dates and checks whether the first date is before the second. I first wrote the ...
6
votes
2answers
215 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 ...