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Create unique constraint with null columns
...or may not be useful. In extreme situations it might even help to maintain all three indexes (the two partial ones and a total on top).
Aside: I advise not to use mixed case identifiers in PostgreSQL.
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Is there a WebSocket client implemented for Python? [closed]
...ient
Sample client code:
#!/usr/bin/python
from websocket import create_connection
ws = create_connection("ws://localhost:8080/websocket")
print "Sending 'Hello, World'..."
ws.send("Hello, World")
print "Sent"
print "Receiving..."
result = ws.recv()
print "Received '%s'" % result
ws.close()
S...
Compare two DataFrames and output their differences side-by-side
...original question
The first step is to concatenate the DataFrames horizontally with the concat function and distinguish each frame with the keys parameter:
df_all = pd.concat([df.set_index('id'), df2.set_index('id')],
axis='columns', keys=['First', 'Second'])
df_all
It's pr...
In Python, how does one catch warnings as if they were exceptions?
...ationWarning)
with warnings.catch_warnings(record=True) as w:
# Cause all warnings to always be triggered.
warnings.simplefilter("always")
# Trigger a warning.
fxn()
# Verify some things
assert len(w) == 1
assert issubclass(w[-1].category, DeprecationWarning)
assert ...
Where is Erlang used and why? [closed]
...ng in its SMS and authentication systems.
• Motorola is using Erlang in call processing products in the public-safety industry.
• Ericsson uses Erlang in its support nodes, used in GPRS and 3G mobile networks
worldwide.
The most popular open source Erlang applications include the following:
•...
How JavaScript closures are garbage collected
...e expected behavior.
From Mozilla's Memory management page: "As of 2012, all modern browsers ship a mark-and-sweep garbage-collector." "Limitation: objects need to be made explicitly unreachable".
In your examples where it fails some is still reachable in the closure. I tried two ways to make it...
What happened to “HelveticaNeue-Italic” on iOS 7.0.3
...
You say you replaced all your uses with something else. What did you replace it with? We noticed that if you replace it with HelveticaNeue-MediumItalic in the XIB file, we get incorrect results on iOS 6 and earlier because that font appears to ha...
When to use static vs instantiated classes
...r BB code to HTML ; it doesn't have a life on its own)
(Yeah, I admit, really really overly-simplified...)
One thing about static methods/classes is that they don't facilitate unit testing (at least in PHP, but probably in other languages too).
Another thing about static data is that only one in...
CSS: background image on background color
...ch I colored blue if this panel is being selected (clicked on it). Additionally, I add a small sign ( .png image) to that panel, which indicates that the selected panel has been already selected before.
...
Why would I use Scala/Lift over Java/Spring? [closed]
...over it. From my perspective and experience, Java Annotations and Spring really minimizes the amount of coding that you have to do for an application. Does Scala/Lift improve upon that?
...