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Creating a singleton in Python
...mple implementation:
class Singleton(type):
_instances = {}
def __call__(cls, *args, **kwargs):
if cls not in cls._instances:
cls._instances[cls] = super(Singleton, cls).__call__(*args, **kwargs)
return cls._instances[cls]
class Logger(object):
__meta...
How can one use multi threading in PHP applications
... PHP documentation:
pthreads is an object-orientated API that provides all of the tools needed for multi-threading in PHP. PHP applications can create, read, write, execute and synchronize with Threads, Workers and Threaded objects.
Warning:
The pthreads extension cannot be used in a web ...
Best way to do multi-row insert in Oracle?
...AG_NAME,PAG_ACTIVE)
select 8000,0,'Multi 8000',1 from dual
union all select 8001,0,'Multi 8001',1 from dual
The thing to remember here is to use the from dual statement.
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How to get name of exception that was caught in Python?
...n't want to catch particular exceptions known in advance. I want to catch all exceptions.
– Rob Bednark
Apr 27 '18 at 16:10
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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
...
What's the difference between :: (double colon) and -> (arrow) in PHP?
... used to access static members, such usage is discouraged), while :: is usually used to access static members (though in a few special cases, it's used to access instance members).
In general, :: is used for scope resolution, and it may have either a class name, parent, self, or (in PHP 5.3) static...
How to serve static files in Flask
...ample below, I have moved my templates and static files into a sub-folder called web.
app = Flask(__name__,
static_url_path='',
static_folder='web/static',
template_folder='web/templates')
static_url_path='' removes any preceding path from the URL (i.e.
the d...
background function in Python
...em is. I've got a function that downloads the image needed and saves it locally. Right now it's run inline with the code that displays a message to the user, but that can sometimes take over 10 seconds for non-local images. Is there a way I could call this function when it's needed, but run it in t...
Why do we always prefer using parameters in SQL statements?
...uld be
SELECT empSalary from employee where salary = 0 or 1=1
whereby all empSalaries would be returned.
Further, a user could perform far worse commands against your database, including deleting it If they wrote 0; Drop Table employee:
SELECT empSalary from employee where salary = 0; Drop Ta...
How to list branches that contain a given commit?
...uery git to find out which branches contain a given commit? gitk will usually list the branches, unless there are too many, in which case it just says "many (38)" or something like that. I need to know the full list, or at least whether certain branches contain the commit.
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