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Strings in a DataFrame, but dtype is object
...ndarray. Every element in a ndarray must has the same size in byte. For int64 and float64, they are 8 bytes. But for strings, the length of the string is not fixed. So instead of save the bytes of strings in the ndarray directly, Pandas use object ndarray, which save pointers to objects, because of ...
What is the difference between MOV and LEA?
... Note that in all of these examples, lea is the worse choice except in 64-bit mode for RIP-relative addressing. mov r32, imm32 runs on more ports. lea eax, [edx*4] is a copy-and-shift which can't be done in one instruction otherwise, but in the same register LEA just takes more bytes to encode...
How are Python's Built In Dictionaries Implemented?
...it is two-thirds full. This avoids slowing down lookups. (see dictobject.h:64-65)
NOTE: I did the research on Python Dict implementation in response to my own question about how multiple entries in a dict can have same hash values. I posted a slightly edited version of the response here because al...
Extract every nth element of a vector
...
niconico
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What killed my process and why?
... 0 0 systemd-journal
Jul 20 11:05:00 someapp kernel: [ 246] 0 246 10494 133 22 0 -1000 systemd-udevd
Jul 20 11:05:00 someapp kernel: [ 264] 0 264 29174 121 26 0 -1000 auditd
Jul 20 11:05:00 someapp kernel: [ 342...
Get current time as formatted string in Go?
... most.
– Roger Hill
Jan 30 '19 at 0:46
I have suggested an edit - Get current time as formatted string in Go?. Hopeful...
String literals: Where do they go?
...ts of the array, the behavior is undefined.
Where do they go?
GCC 4.8 x86-64 ELF Ubuntu 14.04:
char s[]: stack
char *s:
.rodata section of the object file
the same segment where the .text section of the object file gets dumped, which has Read and Exec permissions, but not Write
Program:
#inclu...
Can you require two form fields to match with HTML5?
...
87
Not exactly with HTML5 validation but a little JavaScript can resolve the issue, follow the exa...
Is there a standard sign function (signum, sgn) in C/C++?
...tain the machine's internal high-precision representation (e.g. 80 bit on x87), and avoid a premature round to zero.
Caveats:
It's a template so it might take longer to compile in some circumstances.
Apparently some people think use of a new, somewhat esoteric, and very slow standard library fun...
What is the Swift equivalent to Objective-C's “@synchronized”?
...
– Michael Waterfall
Oct 23 '14 at 16:46
9
With this approach you need to be careful. Your block mi...