Python 3 is the latest version of the Python programming language and was formally released on December 3rd, 2008.
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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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votes
1answer
64 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 ...
0
votes
1answer
34 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 ...
2
votes
1answer
64 views
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 ...
-6
votes
2answers
140 views
What is the most simplified definition for references in Python for a 15 year old? [closed]
I have recently been learning Python and I stumbled across this a problem.....References. I have been learning Python from the automated boring stuff with Python. In that book they used this script ...
1
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2answers
73 views
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 ...
3
votes
3answers
69 views
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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votes
2answers
188 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
72 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 ...
0
votes
1answer
93 views
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 = ...
5
votes
2answers
971 views
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 ...
0
votes
0answers
28 views
Ipython3 development cycle
I am new to python (python3) and am using Ipython3 while writing the code just in my preferred text editor. I am not yet sure what is a good development cycle as I keep getting problems with reloading ...
2
votes
1answer
47 views
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()
...
-3
votes
1answer
433 views
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
votes
1answer
113 views
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
# ...
...
4
votes
3answers
112 views
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):
...
0
votes
0answers
172 views
“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
266 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 ...
1
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1answer
106 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
votes
3answers
206 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
262 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 ...
-3
votes
1answer
216 views
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 ...
-1
votes
1answer
137 views
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 = ...
-4
votes
4answers
151 views
Does this python program obey functional paradigm? [closed]
Below is the hailstone sequence program considering the rule of thumb in functional programming.
The simple rule of thumb is: if you can replace any expression, sub-expression or subroutine call ...
1
vote
1answer
133 views
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 ...
1
vote
1answer
121 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 ...
0
votes
1answer
64 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 ...
1
vote
1answer
77 views
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", ...
40
votes
2answers
4k views
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 ...
13
votes
2answers
9k views
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
votes
2answers
180 views
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) :
...
1
vote
1answer
177 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 ...
1
vote
2answers
196 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 ...
2
votes
2answers
457 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 ...
3
votes
1answer
232 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 ...
0
votes
2answers
1k views
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 ...
16
votes
1answer
675 views
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 ...
3
votes
1answer
2k views
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>
...
1
vote
1answer
313 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 ...
