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Variable is accessed within inner class. Needs to be declared final
...anges made in the inner class did not persist in the enclosing scope. Basically, what happens in the inner class stays in the inner class.
I wrote a more in-depth explanation here. It also explains why instance and global variables do not need to be declared final.
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Calling pylab.savefig without display in ipython
...tion between IPython and matplotlib.pylab in this regard. But, when I call pylab.savefig("test.png") the current figure get's displayed in addition to being saved in test.png . When automating the creation of a large set of plot files, this is often undesirable. Or in the situation that an in...
Blocks and yields in Ruby
...trary segments of code.
When a method expects a block, it invokes it by calling the yield function.
This is very handy, for instance, to iterate over a list or to provide a custom algorithm.
Take the following example:
I'm going to define a Person class initialized with a name, and provide a ...
Get statistics for each group (such as count, mean, etc) using pandas GroupBy?
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What if I have a separate called Counts and instead of count the rows of the grouped type, I need to add along the column Counts.
– Abhishek Bhatia
Oct 2 '17 at 21:28
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How to create JSON string in JavaScript?
... create JSON string just to play around. It's throwing error, but if I put all the name, age, married in one single line (line 2) it doesn't. Whats the problem?
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ggplot with 2 y axes on each side and different scales
I need to plot a bar chart showing counts and a line chart showing rate all in one chart, I can do both of them separately, but when I put them together, I scale of the first layer (i.e. the geom_bar ) is overlapped by the second layer (i.e. the geom_line ).
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How to un-escape a backslash-escaped string?
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Basically for Python3 you want print(b"Hello,\nworld!".decode('unicode_escape'))
– ChristopheD
Apr 7 '15 at 8:35
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How to try convert a string to a Guid [duplicate]
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Specifically, a GUIDConverter, which is built in. msdn.microsoft.com/en-us/library/…
– Joseph Ferris
Dec 8 '08 at 19:11
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How do I delete a fixed number of rows with sorting in PostgreSQL?
...erm row identifier.
There's also oid but that only exists if you specifically ask for it when you create the table.
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How to add an auto-incrementing primary key to an existing table, in PostgreSQL?
...of PostgreSQL
In old versions of PostgreSQL (prior to 8.x?) you had to do all the dirty work. The following sequence of commands should do the trick:
ALTER TABLE test1 ADD COLUMN id INTEGER;
CREATE SEQUENCE test_id_seq OWNED BY test1.id;
ALTER TABLE test ALTER COLUMN id SET DEFAULT nextval('...