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mongo group query how to keep fields
...are accumulated/funneled/reduced) doesn't make so much sense even theoretically. However, sorting before hand is actually inefficient compared to sorting each group within themselves since sorting algorithms are more complex than O(n). I wish there would be better ways in MongoDB.
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Perform an action in every sub-directory using Bash
... command, this is more concise:
for D in *; do [ -d "${D}" ] && my_command; done
Or an even more concise version (thanks @enzotib). Note that in this version each value of D will have a trailing slash:
for D in */; do my_command; done
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Overloaded method selection based on the parameter's real type
...n Java, dynamic method dispatch happens only for the object the method is called on, not for the parameter types of overloaded methods.
Citing the Java Language Specification:
When a method is invoked (§15.12), the
number of actual arguments (and any
explicit type arguments) and the
comp...
Python circular importing?
... of it) for the first time, the code inside the module is executed sequentially like any other code; e.g., it is not treated any differently that the body of a function. An import is just a command like any other (assignment, a function call, def, class). Assuming your imports occur at the top of th...
IE10 renders in IE7 mode. How to force Standards mode?
...imple doctype declaration is enough. But even a document as short as this falls back to IE7 mode:
5 Answers
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How do I look inside a Python object?
...-in functions:
type()
dir()
id()
getattr()
hasattr()
globals()
locals()
callable()
type() and dir() are particularly useful for inspecting the type of an object and its set of attributes, respectively.
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How to see what will be updated from repository before issuing “svn update” command?
...nNumber --summarize
if you want to see what will be updated (without actually updating), run
command:
$ svn merge --dry-run -r BASE:HEAD .
if you want to know what content of a particular file has been changed in svn
server repository compared with your working copy, run command:
$ svn dif...
Add params to given URL in Python
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@florian : At least in python 2.7 you then need to call urlencode as urllib.urlencode(query, doseq=True). Otherwise, parameters that existed in the original url are not preserved correctly (because they are returned as tuples from @parse_qs@
– rluba
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Difference between timestamps with/without time zone in PostgreSQL
...rpreted.
The effects of time zones on these data types is covered specifically in the docs. The difference arises from what the system can reasonably know about the value:
With a time zone as part of the value, the value can be rendered as a local time in the client.
Without a time zone as part o...
What is the difference between “screen” and “only screen” in media queries?
... to apply these styles. At that size you would be talking about anything smaller than a desktop screen in most cases.
@media screen and (max-width:632px)
This one is saying for a device with a screen and a window with max-width of 632px apply the style. This is almost identical to the above exce...