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Permanently add a directory to PYTHONPATH?
...n environment variable in your chosen platform and shell, since it's not really a programming question per se.
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Counting the Number of keywords in a dictionary in python
... the len() function.
> a = {'foo':42, 'bar':69}
> len(a)
2
To get all the distinct words (i.e. the keys), use the .keys() method.
> list(a.keys())
['foo', 'bar']
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Test whether a list contains a specific value in Clojure
...ex 0!).
To add to the confusion, in cases where it doesn't make sense to call contains?, it simply return false; this is what happens in (contains? :foo 1) and also (contains? '(100 101 102) 101). Update: In Clojure ≥ 1.5 contains? throws when handed an object of a type that doesn't support the i...
What is the JavaScript convention for no operation?
... "function" // returns true
It can be invoked as a function and essentially does nothing as shown here:
setTimeout(function() {
console.log('Start: ', Date.now());
Function.prototype();
console.log('End : ', Date.now());
}, 1000);
Although this is a "true noop" since...
Should I use `import os.path` or `import os`?
...ant to use rather than a thing in the os module, so even though it's not really a submodule of a package called os, I import it sort of like it is one and I always do import os.path. This is consistent with how os.path is documented.
Incidentally, this sort of structure leads to a lot of Python p...
pretty-print JSON using JavaScript
...s + '">' + match + '</span>';
});
}
var obj = {a:1, 'b':'foo', c:[false,'false',null, 'null', {d:{e:1.3e5,f:'1.3e5'}}]};
var str = JSON.stringify(obj, undefined, 4);
output(str);
output(syntaxHighlight(str));
pre {outline: 1px solid #ccc; padding: 5px; margin: 5px; }
.string...
How to remove a field from params[:something]
... = params.except[the one I wish to remove]
This is a safer way to 'grab' all the params you need into a copy WITHOUT destroying the original passed in params (which is NOT a good thing to do as it will make debugging and maintenance of your code very hard over time).
Or you could just pass direc...
ALTER TABLE to add a composite primary key
I have a table called provider . I have three columns called person , place , thing . There can be duplicate persons, duplicate places, and duplicate things, but there can never be a dupicate person-place-thing combination.
...
关于jQuery的AJAX不兼容IE的解决办法 - 更多技术 - 清泛网 - 专注C/C++及内核技术
...查看手册后发现请求的数据格式还是有一种JSON格式，如{foo:["bar1", "bar2"]} ，然后就按照这种格式书写，还真的返回了正确的查询结果。真不知道IE还有这点要求。（完）
先前的格式：
type: "get",
data: "bid="+my_bid+"&name_cn="+...
Deleting Objects in JavaScript
...a C++ delete. (And accessing one of them would cause a crash. To make them all turn null would mean having extra work when deleting or extra memory for each object.)
Since Javascript is garbage collected, you don't need to delete objects themselves - they will be removed when there is no way to ref...