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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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Do something if screen width is less than 960 px
How can I make jQuery do something if my screen width is less than 960 pixels? The code below always fires the 2nd alert, regardless of my window size:
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Replace values in list using Python [duplicate]
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Build a new list with a list comprehension:
new_items = [x if x % 2 else None for x in items]
You can modify the original list in-place if you want, but it doesn't actually save time:
items = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
for index, item in enumerate(items):
if not (item ...
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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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 >...
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...
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...
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...
How to determine whether an object has a given property in JavaScript
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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...