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What is the difference between class and instance attributes?
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Only the mutable types are shared. Like for int and str they still attached with each instances rather than class.
– Babu
Jul 17 '14 at 11:59
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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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What is the difference between “JPG” / “JPEG” / “PNG” / “BMP” / “GIF” / “TIFF” Image?
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Yes. They are different file formats (and their file extensions).
Wikipedia entries for each of the formats will give you quite a bit of information:
JPEG (or JPG, for the file extension; Joint Photographic Experts Group)
PNG (Portable Network Graphics)
BMP (B...
Rails 4: assets not loading in production
I'm trying to put my app into production and image and css asset paths aren't working.
18 Answers
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“x not in y” or “not x in y”
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They always give the same result.
In fact, not 'ham' in 'spam and eggs' appears to be special cased to perform a single "not in" operation, rather than an "in" operation and then negating the result:
>>> import dis
>>> def notin():
'ham' not in 'spam and eggs'
&g...
When would you use a WeakHashMap or a WeakReference?
...mplementation of so I'm trying to figure out what the use case for them is and how the implementation would work. When have you needed to use a WeakHashMap or WeakReference and how was it used?
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Ruby optional parameters
...his method: e.g. If you're trying to make the default value for scope true and you pass in false, scope ||= true won't work. It evaluates the same as nil and will set it to true
– Joshua Pinter
Nov 10 '11 at 5:32
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right click context menu for datagridview
... a datagridview in a .NET winform app. I would like to rightclick on a row and have a menu pop up. Then i would like to select things such as copy, validate, etc
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Distributed sequence number generation?
...m first seeing now.
You'll need to differentiate between sequence numbers and unique IDs that are (optionally) loosely sortable by a specific criteria (typically generation time). True sequence numbers imply knowledge of what all other workers have done, and as such require shared state. There is n...
What is the scope of variables in JavaScript?
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TLDR
JavaScript has lexical (also called static) scoping and closures. This means you can tell the scope of an identifier by looking at the source code.
The four scopes are:
Global - visible by everything
Function - visible within a function (and its sub-functions and blocks)
Bloc...