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What is the syntax rule for having trailing commas in tuple definitions?
...
In all cases except the empty tuple the comma is the important thing. Parentheses are only required when required for other syntactic reasons: to distinguish a tuple from a set of function arguments, operator precedence, or to a...
Django TemplateDoesNotExist?
... assuming that you have the apps configured in settings.py like this:
INSTALLED_APPS = (
'appname1',
'appname2',
'appname3',
)
By default Django will load the templates under templates/ directory under every installed apps. So with your directory structure, we want to move our templat...
When should I use the Visitor Design Pattern? [closed]
...want to make the fewest possible modifications to it.
The Visitor pattern allows you to move each new operation in a suitable class, and you need to extend the hierarchy's interface only once. Let's do it. First, we define an abstract operation (the "Visitor" class in GoF) which has a method for ev...
SqlAlchemy - Filtering by Relationship Attribute
...ts = Patient.query.filter(Patient.mother.has(phenoscore=10))
or join (usually faster):
patients = Patient.query.join(Patient.mother, aliased=True)\
.filter_by(phenoscore=10)
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Unix's 'ls' sort by name
...t the FILEs (the current directory by default). Sort entries alpha‐betically if none of -cftuvSUX nor --sort is specified.:
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Installing Python 3 on RHEL
I'm trying to install python3 on RHEL using the following steps:
19 Answers
19
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How to dynamically create a class?
...ou can modify GetTypeBuilder() method and change moduleBuilder.DefineType call to include the static type as the last parameter (is null now)
– danijels
Oct 5 '10 at 9:49
2
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INSERT INTO…SELECT for all MySQL columns
... syntax, it looks like this (leave out the column list to implicitly mean "all")
INSERT INTO this_table_archive
SELECT *
FROM this_table
WHERE entry_date < '2011-01-01 00:00:00'
For avoiding primary key errors if you already have data in the archive table
INSERT INTO this_table_archive
SELECT...
What is the definition of “interface” in object oriented programming
... one of the more overloaded and confusing terms in development.
It is actually a concept of abstraction and encapsulation. For a given "box", it declares the "inputs" and "outputs" of that box. In the world of software, that usually means the operations that can be invoked on the box (along with ar...
How do I import CSV file into a MySQL table?
... MySQL table so that I can refactor into a sane format. I created a table called 'CSVImport' that has one field for every column of the CSV file. The CSV contains 99 columns , so this was a hard enough task in itself:
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