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What is the most efficient string concatenation method in python?
... idiomatic and thus easier for other python programmers to understand.
Finally, the golden rule of optimization: don't optimize unless you know you need to, and measure rather than guessing.
You can measure different methods using the timeit module. That can tell you which is fastest, instead of r...
Are list-comprehensions and functional functions faster than “for loops”?
...ike map() , filter() and reduce() faster than a for loop? Why, technically, they run in a C speed , while the for loop runs in the python virtual machine speed ?.
...
Polymorphism in C++
...ecific code selected?
Run time means the compiler must generate code for all the types the program might handle while running, and at run-time the correct code is selected (virtual dispatch)
Compile time means the choice of type-specific code is made during compilation. A consequence of this: say...
Python module for converting PDF to text [closed]
... updated again in version 20100213
You can check the version you have installed with the following:
>>> import pdfminer
>>> pdfminer.__version__
'20100213'
Here's the updated version (with comments on what I changed/added):
def pdf_to_csv(filename):
from cStringIO import S...
How to check that an element is in a std::set?
... Note that using count() instead of find() is never better but potentially worse. This is because find() will return after the first match, count() will always iterate over all elements.
– Frerich Raabe
Nov 9 '09 at 15:50
...
Macro vs Function in C
...uct webpage page;
page.numButtons = 2;
num_button_holes(page) -> 8
Finally, macros can be difficult to debug, producing weird syntax errors or runtime errors that you have to expand to understand (e.g. with gcc -E), because debuggers cannot step through macros, as in this example:
#define prin...
How do I implement interfaces in python?
...interface, a module that is a part of the Zope Component Architecture, a really awesomely cool component framework. Here you don't subclass from the interfaces, but instead mark classes (or even instances) as implementing an interface. This can also be used to look up components from a component reg...
How do I spool to a CSV formatted file using SQLPLUS?
...tion on IDs)
spool myfile.csv
select table_name, tablespace_name
from all_tables
where owner = 'SYS'
and tablespace_name is not null;
Output will be like:
TABLE_PRIVILEGE_MAP ,SYSTEM
SYSTEM_PRIVILEGE_MAP ,SYSTEM
...
detach all packages while working in R
...*) is not necessary but can be useful to prevent the NULL reply from vertically spamming the R window.
(edit: 9/20/2019) In version 3.6.1
It may be helpful to convert loaded only names(sessionInfo()$loadedOnly) to explicitly attached packages first, and then detach the packages, as so.
lapply(names(...
How can I convert JSON to CSV?
...
First, your JSON has nested objects, so it normally cannot be directly converted to CSV. You need to change that to something like this:
{
"pk": 22,
"model": "auth.permission",
"codename": "add_logentry",
"content_type": 8,
"name": "Can add log entry"...