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How do you query for “is not null” in Mongo?
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db.collection_name.find({"filed_name":{$exists:true}});
fetch documents that contain this filed_name even it is null.
My proposition:
db.collection_name.find({"field_name":{$type:2}}) //type:2 == String
You can check on the required...
How to use permission_required decorators on django class-based views
...m, specific permissions. In function-based views I do that with @permission_required() and the login_required attribute in the view, but I don't know how to do this on the new views. Is there some section in the django docs explaining this? I didn't found anything. What is wrong in my code?
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Generate a heatmap in MatPlotLib using a scatter data set
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x = y = NP.linspace(-5, 5, 100)
X, Y = NP.meshgrid(x, y)
Z1 = ML.bivariate_normal(X, Y, 2, 2, 0, 0)
Z2 = ML.bivariate_normal(X, Y, 4, 1, 1, 1)
ZD = Z2 - Z1
x = X.ravel()
y = Y.ravel()
z = ZD.ravel()
gridsize=30
PLT.subplot(111)
# if 'bins=None', then color of each hexagon corresponds directly to i...
How to check if an object is a list or tuple (but not string)?
...quence; otherwise, if it is indexable or iterable, it's a sequence:
def is_sequence(arg):
return (not hasattr(arg, "strip") and
hasattr(arg, "__getitem__") or
hasattr(arg, "__iter__"))
def srepr(arg):
if is_sequence(arg):
return '<' + ", ".join(srepr(x) f...
How to make a phone call in android and come back to my activity when the call is done?
...ener actions to wait for a the call to start (wait until changed from PHONE_STATE_OFFHOOK to PHONE_STATE_IDLE again) and then write some code to bring your app back up on the IDLE state.
you may need to run the listener in a service to ensure it stays up and your app is restarted. some example c...
How can I listen for a click-and-hold in jQuery?
...tartTrigger(e) {
var $elem = $(this);
$elem.data('mouseheld_timeout', setTimeout(function() {
$elem.trigger('mouseheld');
}, e.data));
}
function stopTrigger() {
var $elem = $(this);
clearTimeout($elem.data('mouseheld_timeout'));
}
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Add Text on Image using PIL
...m PIL import ImageFont
from PIL import ImageDraw
img = Image.open("sample_in.jpg")
draw = ImageDraw.Draw(img)
# font = ImageFont.truetype(<font-file>, <font-size>)
font = ImageFont.truetype("sans-serif.ttf", 16)
# draw.text((x, y),"Sample Text",(r,g,b))
draw.text((0, 0),"Sample Text",(...
How can I get the current screen orientation?
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This only provides two values ORIENTATION_PORTRAIT and ORIENTATION_LANDSCAPE. Is there a way to get all the four values from ActivityInfo? (That is LANDSCAPE_REVERSE and PORTRAIT_REVERSE as well)
– HRJ
May 4 '11 at 9:56
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Git Bash is extremely slow on Windows 7 x64
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Problem is with $(__git_ps1) ... removing this makes everything superfast
– Hendy Irawan
Apr 7 '15 at 3:27
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Understanding slice notation
...asic sequences don't support them.
>>> class slicee:
... def __getitem__(self, item):
... return repr(item)
...
>>> slicee()[0, 1:2, ::5, ...]
'(0, slice(1, 2, None), slice(None, None, 5), Ellipsis)'
...