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How does zip(*[iter(s)]*n) work in Python?
...re you're passing the same iterator 3 times to zip(), and it pulls an item from the iterator each time.
x = iter([1,2,3,4,5,6,7,8,9])
print zip(x, x, x)
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Defining a variable with or without export
...e=value
means that the variable name is available to any process you run from that shell process. If you want a process to make use of this variable, use export, and run the process from that shell.
name=value
means the variable scope is restricted to the shell, and is not available to any othe...
JavaScript: Passing parameters to a callback function
...e callback function
//only when we have some missing value
//get this data from ajax or compute
var extraParam = "this data was missing" ;
//call the callback when we have the data
callback(extraParam);
}
// test function
callbackTester (function(k) {
tryMe("hello", "goodbye", k);
});
...
How to execute mongo commands through shell scripts?
...u'll want to surround the eval argument in single quotes to keep the shell from evaluating the operator as an environment variable:
mongo --eval 'db.mycollection.update({"name":"foo"},{$set:{"this":"that"}});' myDbName
Otherwise you may see something like this:
mongo --eval "db.test.update({\"na...
Why is it considered a bad practice to omit curly braces? [closed]
...ames in filesystem walks), though, where blank lines help setting them off from the main code.
– Alan Plum
Feb 5 '10 at 0:10
1
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How do I enable EF migrations for multiple contexts to separate databases?
...I just bumped into the same problem and I used the following solution (all from Package Manager Console)
PM> Enable-Migrations -MigrationsDirectory "Migrations\ContextA" -ContextTypeName MyProject.Models.ContextA
PM> Enable-Migrations -MigrationsDirectory "Migrations\ContextB" -ContextTypeNam...
How to disable margin-collapsing?
...nt collapse only in the latter case. Also, any value of overflow different from its default (visible) applied to the parent will prevent collapse. Thus, both overflow: auto and overflow: hidden will have the same effect. Perhaps the only difference when using hidden is the unintended consequence of ...
What is an example of the simplest possible Socket.io example?
...
// Respond with a message including this clients' id sent from the server
socket.emit('i am client', {data: 'foo!', id: data.id});
});
socket.on('time', function(data) {
addMessage(data.time);
});
socket...
Streaming via RTSP or RTP in HTML5
I'm building a web app that should play back an RTSP/RTP stream from a server http://lscube.org/projects/feng .
8 Answers
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What are the applications of binary trees?
...no real speed advantage.
In a (balanced) binary tree with m nodes, moving from one level to the next requires one comparison, and there are log_2(m) levels, for a total of log_2(m) comparisons.
In contrast, an n-ary tree will require log_2(n) comparisons (using a binary search) to move to the next...