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How to concatenate two MP4 files using FFmpeg?
...pe f is for only listing files. I added | sort to sort the files alphabetically; because find reads them in order as saved on filesystem. Works also for files with whitespaces.
– erik
Dec 2 '16 at 14:15
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Efficient way to apply multiple filters to pandas DataFrame or Series
...s to apply several filters to a Pandas DataFrame or Series object. Essentially, I want to efficiently chain a bunch of filtering (comparison operations) together that are specified at run-time by the user.
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Getting HTTP code in PHP using curl
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First make sure if the URL is actually valid (a string, not empty, good syntax), this is quick to check server side. For example, doing this first could save a lot of time:
if(!$url || !is_string($url) || ! preg_match('/^http(s)?:\/\/[a-z0-9-]+(.[a-z0-9-]+)*...
Does Python optimize tail recursion?
...tracebacks:
Tail Recursion Elimination (2009-04-22)
Final Words on Tail Calls (2009-04-27)
You can manually eliminate the recursion with a transformation like this:
>>> def trisum(n, csum):
... while True: # Change recursion to a while loop
... if n == 0:...
Is there a generator version of `string.split()` in Python?
...plitlines chops off the trainling newline though (something that I don't really like...); if you wanted to replicated that part of the behavior, you could use grouping: (m.group(2) or m.group(3) for m in re.finditer('((.*)\n|(.+)$)', s)). PS: I guess the outer paren in the RE are not needed; I just ...
When do we need curly braces around shell variables?
...xpand the variable identified by foobar.
Curly braces are also unconditionally required when:
expanding array elements, as in ${array[42]}
using parameter expansion operations, as in ${filename%.*} (remove extension)
expanding positional parameters beyond 9: "$8 $9 ${10} ${11}"
Doing this every...
Ship an application with a database
... for creating and updating databases.
One is to create a database externally, then place it in the assets folder of the project and then copy the entire database from there. This is much quicker if the database has a lot of tables and other components. Upgrades are triggered by changing the dat...
How to limit the maximum value of a numeric field in a Django model?
...ormer can be restricted to the number of decimal places stored and the overall number of characters stored, is there any way to restrict it to storing only numbers within a certain range, e.g. 0.0-5.0 ?
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Decompressing GZip Stream from HTTPClient Response
I am trying to connect to an api, that returns GZip encoded JSON, from a WCF service (WCF service to WCF service). I am using the HTTPClient to connect to the API and have been able to return the JSON object as a string. However I need to be able to store this returned data in a database and as su...
Why is TypedReference behind the scenes? It's so fast and safe… almost magical!
...ecification, the constructs used to implement them under the hood (vararg calling convention, TypedReference type, arglist, refanytype, mkanyref, and refanyval instructions) are perfectly documented in the CLI Specification (ECMA-335) in the Vararg library.
Being defined in the Vararg Library makes ...