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Is there a simple, elegant way to define singletons? [duplicate]
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I don't really see the need, as a module with functions (and not a class) would serve well as a singleton. All its variables would be bound to the module, which could not be instantiated repeatedly anyway.
If you do wish to use a class, there is no way of creating private classes...
What does “Content-type: application/json; charset=utf-8” really mean?
...om the content itself, i.e. you can't necessarily just look at the content and know what to do with it. That's what HTTP headers are for, they tell the recipient what kind of content they're (supposedly) dealing with.
Content-type: application/json; charset=utf-8 designates the content to be in JSO...
Drop all duplicate rows across multiple columns in Python Pandas
The pandas drop_duplicates function is great for "uniquifying" a dataframe. However, one of the keyword arguments to pass is take_last=True or take_last=False , while I would like to drop all rows which are duplicates across a subset of columns. Is this possible?
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How can I get the intersection, union, and subset of arrays in Ruby?
...n do set operations on arrays by doing &(intersection), -(difference), and |(union).
Obviously I didn't implement the MultiSet to spec, but this should get you started:
class MultiSet
attr_accessor :set
def initialize(set)
@set = set
end
# intersection
def &(other)
@set &...
Difference between window.location.href, window.location.replace and window.location.assign
...rl;
They simply navigate to the new URL. The replace method on the other hand navigates to the URL without adding a new record to the history.
So, what you have read in those many forums is not correct. The assign method does add a new record to the history.
Reference: http://developer.mozilla.org/...
The name 'model' does not exist in current context in MVC3
...;host> line.
Well, I found myself experiencing the same thing you did, and after a bit further research, I found out what the problem is!
You need to include the default MVC3 web.config for the Views folder. MVC3 has two: one in the root for your application, and one for the views folder. Thi...
Generate array of all letters and digits
Using ruby, is it possible to make an array of each letter in the alphabet and 0-9 easily?
7 Answers
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Does MySQL ignore null values on unique constraints?
...sult:
x
NULL
NULL
1
This is not true for all databases. SQL Server 2005 and older, for example, only allows a single NULL value in a column that has a unique constraint.
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How can you undo the last git add?
...valid ref. I haven't committed anything yet (new repo) just done git add . and regretted it. I don't want to reset the entire add, just one directory. git reset -- dir/*.* generates the error above.
– Francis Davey
Jan 23 '14 at 17:51
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How can I close a buffer without closing the window?
Vim's multilayered views (Windows, Buffers and Tabs) left me a little confused. Let's say I split the display (:sp) and then select a different buffer to display in each window. Now I want to close one of the buffers, yet I don't want the window to close (After the closing it can display the next bu...