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SQLAlchemy: Creating vs. Reusing a Session
...ing the resulting Session() class each time you need to talk to your DB. For me that means the second I would do my first session.add(x) or something similar, I would first do
...
Can I get a patch-compatible output from git-diff?
...commits combined with rebase, git stash and bundles are easier to manage.
For your use case I think that stash is most appropriate.
# save uncommitted changes
git stash
# do a merge or some other operation
git merge some-branch
# re-apply changes, removing stash if successful
# (you may be asked...
Why use Ruby's attr_accessor, attr_reader and attr_writer?
...s class and after that remains constant. If there were a mutator (writer) for age and the class were written assuming that age, once set, does not change, then a bug could result from code calling that mutator.
But what is happening behind the scenes?
If you write:
attr_writer :age
That gets t...
What are dictionary view objects?
...tems) of a dictionary. Here is an excerpt from the official documentation for Python 3:
>>> dishes = {'eggs': 2, 'sausage': 1, 'bacon': 1, 'spam': 500}
>>> keys = dishes.keys()
>>> values = dishes.values()
>>> # view objects are dynamic and reflect dict change...
What is the purpose of `text=auto` in `.gitattributes` file?
...ocs:
Each line in .gitattributes (or .git/info/attributes) file is of form:
pattern attr1 attr2 ...
So here, the pattern is *, which means all files, and the attribute is text=auto.
What does text=auto do? From the documentation:
When text is set to "auto", the path is marked for autom...
How to track down log4net problems
...thing I've never figured out is how to tell what's going on on the inside. For example, I've got a console appender and a database appender in my project. I made a few changes to the database and the code, and now the database appender doesn't work anymore. I'll figure out why eventually, but it wou...
Is there any way in C# to override a class method with an extension method?
... no.
But otherwise you need to use inheritance to do what you are looking for.
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Current time formatting with Javascript
I want to get current time in a specific format with javascript.
14 Answers
14
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Prepend a level to a pandas MultiIndex
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This is especially nice for adding a level to the columns by adding axis=1, since the df.columns doesn't have the "set_index" method like the index, which always bugs me.
– Rutger Kassies
Feb 10 '17 at 12:32
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Why does the C++ map type argument require an empty constructor when using []?
...Constructible and Assignable.
There are also other specific requirements for particular containers as well, such as being Comparable (e.g. for keys in a map).
Incidentally, the following compiles with no error on comeau:
#include <map>
class MyClass
{
public:
MyClass(int t);
};
int...