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MongoDB atomic “findOrCreate”: findOne, insert if nonexistent, but do not update
...the title says, I want to perform a find (one) for a document, by _id, and if doesn't exist, have it created, then whether it was found or was created, have it returned in the callback.
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mkdir -p functionality in Python [duplicate]
...system call. I am sure the code is less than 20 lines, and I am wondering if someone has already written it?
12 Answers
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Detect if homebrew package is installed
I'm about to write a shell script to detect if several homebrew packages are installed in the system. Is there a way to use a brew command to achieve that?
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How do I check if a string is unicode or ascii?
...You can tell which using code something like this:
def whatisthis(s):
if isinstance(s, str):
print "ordinary string"
elif isinstance(s, unicode):
print "unicode string"
else:
print "not a string"
This does not distinguish "Unicode or ASCII"; it only distinguish...
Is there a way to define a min and max value for EditText in Android?
...input = Integer.parseInt(dest.toString() + source.toString());
if (isInRange(min, max, input))
return null;
} catch (NumberFormatException nfe) { }
return "";
}
private boolean isInRange(int a, int b, int c) {
return b > a ? c >...
What's the scope of a variable initialized in an if statement?
... function, class, or module in which they're assigned. Control blocks like if and while blocks don't count, so a variable assigned inside an if is still scoped to a function, class, or module.
(Implicit functions defined by a generator expression or list/set/dict comprehension do count, as do lambd...
Android Fragment handle back button press [duplicate]
...ace( R.id.fragment, new MyFragment() ).addToBackStack( "tag" ).commit();
If you require more detailed control (i.e. when some Fragments are visible, you want to suppress the back key) you can set an OnKeyListener on the parent view of your fragment:
//You need to add the following line for this s...
How to determine whether an object has a given property in JavaScript
...
Object has property:
If you are testing for properties that are on the object itself (not a part of its prototype chain) you can use .hasOwnProperty():
if (x.hasOwnProperty('y')) {
// ......
}
Object or its prototype has a property:
You ca...
Check, using jQuery, if an element is 'display:none' or block on click
...hidden');
visibleElements = $(':visible');
To check particular element.
if($('#yourID:visible').length == 0)
{
}
Elements are considered visible if they consume space in the document.
Visible elements have a width or height that is greater than zero,
Reference
You can also use is() wi...
How to check if the user can go back in browser history or not
I want using JavaScript to see if there is history or not, I mean if the back button is available on the browser or not.
18...