Python 3 is the latest version of the Python programming language and was formally released on December 3rd, 2008.

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Variables (scalars and matrices) assignment in Python

Here are the two cases under consideration. (a)Scalars and (b) Numpy matrices. My query is about initialization and assignment. 1 Perfect y = x = 0; x = 7 print(x,y) y = 8 print(x,y) x=10 ...
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How to generate random Boolean functions in Algebraic Normal Form in Python?

I am looking at A SAT-based Public Key Cryptography Scheme and got inspired to challenge myself to write an implementation of this Cryptography Scheme on Python. A part of the cipher encoding would ...
2
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1answer
160 views

python: detecting if my method is called with 0 or 1 args

I want to write a suite of methods that act as getters when passed zero arguments and as setters when passed a single argument. I have two two reasonable implementations, shown below. Is one better ...
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2answers
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Modelling a REST Object Question (Python)

I have a REST API that I want to model in a class so I can access the properties using the dot notation (JS list notation). I explicately defined the properties on my class using the @property tags ...
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Is using nested function calls a bad thing?

In a recent homework assignment I ended up calling my functions in an ugly way uglyReceipt(cashParser(cashInput())) the program itself worked perfectly but I still felt like I was doing something ...
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221 views

Why Variables in Python Are Different from Other Programming Languages? [closed]

According to my understanding, a variable in Python is: A name that refers to a value stored in the computer memory, and it's like a label on a box. but in other programming languages it is: ...
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Are Python mixins an anti-pattern?

I'm fully aware that pylint and other static analysis tools are not all-knowing, and sometimes their advice must be disobeyed. (This applies for various classes of messages, not just conventions.) ...
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0answers
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Does PyPy or Jython run untrusted Python 3 code more secure while still being fast?

I know that one can not securely restrict normal CPython's capabilities to properly run foreign code without allowing it to access some builtins like open() or allowing other kinds of I/O. So I ...
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3answers
169 views

Why don't empty iterables in python raise Exceptions when you try to iterate over them [duplicate]

I find this behaviour in Python quite peculiar and I believe it can lead to many bugs especially if you have a function/method that takes in a list and returns another list after carrying out some ...
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Why is Python 3.4 still developed after the release of 3.5? [closed]

The lastest version of Python is 3.5.1. However, the latest release is 3.4.4. Why is 3.4.x still developed? Are there breaking changes in 3.5 with respect to 3.4? https://www.python.org/downloads/
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Developing an app using Django. Do I design front-end after app? Or develop Django to fit UI? [duplicate]

Edit: this differs from a similar question because I'm interested specifically in how Django works with the front-end. I.e. what is considered best practice when developing using the Django framework. ...
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1answer
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Multiprocessing usage and limitations [closed]

I'm not able to find any definite answers in the Python Docs. I'm looking for the limitations in 3.5 on MultiProcessing and using a worker pool. Are worker pools functionally limited to the number ...
5
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107 views

Object-Oriented design to create Images in Python

I'm creating images with centered text. I use Python but I'm faced with many question regarding how to write my class. I know that A class must aim to do one thing and do it well. Well, the ...
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0answers
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Is the logic behind `Asyncio.wait()` and async/await, the same, just the code is written differently (syntax)?

I'm learning Python, more specially parallel programming using Python Parallel Programming Cookbook by Giancarlo Zaccone. At the time the book was published async/await was still in the beta version ...
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0answers
141 views

Why use Python's asyncio with coroutines to implement a server

I use Python's asyncio library to create a server that can handle telnet requests. Because asyncio's server loop is single threaded, I thought it would make more sense that when asyncio tells me that ...
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1answer
152 views

What i and n stand for in python? [duplicate]

I've been writing a program to pick random words from my list. However, to do that I had to imitate some solutions on the internet, and I succeeded. Unfortunately, there is something that I can't ...
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1answer
56 views

Are there any pitfalls when replacing a Python module using sys.modules?

In a current project of mine, I have decided to not put any significant amount of code in __init__.py files, simply because I don't like them. In my head, an __init__.py file is just there to inform ...
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1answer
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How does the Python runtime know which object a method is bound to?

When defining methods in a class we do have an argument for the object on which the method is invoked i.e self. Say I have a class Foo. class Foo: def m(self): pass now when we have an ...
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How to achieve inheritance when using just modules and vanilla functions in Python?

Python doesn't enforce any paradigm. It gives you freedom. Python provides encapsulation at module level. If I have a module A and have a module B with same interface. How do I sort of inherit B ...
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Premature memoization on obvious cases

In the code below there will be several instances of MainClass. class MainClass(object): def f(self, x): # expensive operations. # ... return 'something' Each instance ...
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2answers
203 views

Ensuring program output is always the same [closed]

I am working on a +10k LOC program, and I need to ensure its output is always the same for given input. The program consists of dozens of modules and classes, inherited by a MainClass. (The examples ...
0
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1answer
91 views

How to properly handle indefinite generators in Python

Let's say we have a generator that is indefinite, where new elements can arrive at any moment with significant (up to indefinite) delay. An example of such generator is tail -F command. In python (...
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1answer
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Can I listen on a port without interrupting traffic?

I have developed the bare bones on a socket server in Python. I'm trying to capture the HTTP packets going to a web server without blocking them. try: self.socket = socket.socket(socket....
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2answers
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Does this code follow duck typing?

The principle of duck typing says that you shouldn't care what type of object you have - just whether or not you can do the required action with your object. For this reason the isinstance keyword is ...
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1answer
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log method calls per object

How to log method calls on a per object basis for a particular class? I.e. after instanciating a = myClass() I somehow want to keep a log for what methods have been called on a like a.reverse() a....
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Dictionary representation of an object

As python memory model is dictionaries of dictionaries, looks like any object in JavaScript has similar representation. Below code, > foo = {} makes foo as an empty dictionary {}. fine. If ...
2
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1answer
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Break big method into 2 methods, first containing a “for” loop and second a “break”

A method grew too big for its own good, and I need to break it up into two separate methods. def big_method(dct): # Initial code # ... for i in dct: # More code # ... ...
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3answers
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Parent class using methods defined in child

I am working on a large program (more than 10k lines of code). Below is a (hopefully not over-simplified) example of a problem I sometimes face: class MyClass1(object): def func_1(self): ...
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“Python interpreter vs Javascript engine” memory model

I learnt that memory model of python interpreter is dictionaries of dictionaries, where each module is a dictionary. Let me elaborate more on this with an example, After i run >>> python ...
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2answers
901 views

'Tuple' vs 'List' operations in python

Only two operations are allowed on tuple, as shown below. Operations like insert / delete at an index is not allowed. I learnt that tuple is an immutable data model. list allows insert and delete ...
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1answer
115 views

More efficient alternative that checks if a list can be made a palindrome

I asked this question on Stackoverflow, but they told me this is the best place to ask. For my algorithms and data structures class, I have to write an algorithm that is more efficient in the worst ...
3
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3answers
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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 ...
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342 views

Building Data abstraction for rational numbers using “objects”

I follow this definition of "object":An object is a value exporting a procedural interface to data or behavior. Objects use procedural abstraction for information hiding, not type abstraction. Object ...
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Why every value is an object in python? [closed]

I know about writing programs (using C) that have: Data values, that are manipulated. For example: integer, float values etc.. functions (rules), by which data values are manipulated. object is a ...
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Significance of '__name__ ' attribute in python

1) Below python code, >>> def f(): return creates a function type object which has __name__ attribute with value 'f' which looks fine. But, 2) Below line of code, >>> x = ...
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1answer
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How do I enforce 'referential transparency' in this program?

Below is the python program written to follow the rule of thumb in functional programming. The simple rule of thumb is: if you can replace any expression, sub-expression or subroutine call with ...
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1answer
176 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 ...
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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 ...
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1answer
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Is this type of data insertion safe and can stop sql injection in Python?

I am learning Database connection from MySQL Connector/Python Developer Guide. This is the code I am using to insert data: conn = mysql.connector.connect(user="user", password="password", host="127....
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Why do some languages round to the nearest EVEN integer?

Programming languages like Scheme (R5RS) and Python (see this Question) round towards the nearest even integer when value is exactly between the surrounding integers. What is the reasoning behind ...
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Why doesn't Python have a “flatten” function for lists?

Erlang and Ruby both come with functions for flattening arrays. It seems like such a simple and useful tool to add to a language. One could do this: >>> mess = [[1, [2]], 3, [[[4, 5]], 6]] &...
2
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2answers
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Is this looping solution possible with recursion?

Eventually, I would like to generalize this solutions to work with a Tuple of any length. I think recursion is required for that, but I haven't been able to do it. def combineRanges(maxValues) : ...
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1answer
220 views

Additional actions in setup.py for install

Background So, I'm developing a project, and I'm writing setup.py script for it, using distutils. I'm using CPython3.3. I use some libraries that have invalid distributions in PyPI, so they have to ...
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2answers
227 views

Is using os.environ to store the value of command line switches pythonic?

I write CLI-executable Python 3 scripts regularly to do data compilation and some maintenance tasks, and try to adhere to PEP 8 and the Google Python Style Guide when doing so. Google's guide says to ...
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2answers
534 views

What was the need of introducing Python 3 when we already had Python 2 [duplicate]

I am still learning python and I started with Python 3. This question not Python 2 vs 3 or difference between them like print() is a function and not language construct and 3/2 = 1.5 My question is ...
4
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1answer
259 views

What is the advantage of determining scopes statically and using them dynamically in case of Python?

Firstly let me clarify that I know C and am learning Python. So my OOPS is kind of bad. I was reading the official tutorial and found this Although scopes are determined statically, they are ...
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Why do people consider Python a weak language? [closed]

I've been using Python for a little while now and I am enjoying it, but a few of my friends are telling me to start using a language like C# or Java instead and give these reasons: Python is a ...
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What are the problems python 3 new features solve? [closed]

Python 3 new features say: we’re mostly fixing well-known annoyances and warts, and removing a lot of old cruft It mentions what is different (the fix) but not why (the problems). I have have ...
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understanding the encoding scheme in python 3

I got this error in my program which grab data from different website and write them to a file: 'charmap' codec can't encode characters in position 151618-151624: character maps to <undefined> ...
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327 views

What features are missing from Python IDE tools?

What are the most desired features currently lacking in any Python IDE tools? I'm also interested in what's missing in Komodo 6 but available in other tools (I currently use Komodo 6 for Python 3 ...