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pandas: filter rows of DataFrame with operator chaining
... boolean index.
In [96]: df
Out[96]:
A B C D
a 1 4 9 1
b 4 5 0 2
c 5 5 1 0
d 1 3 9 6
In [99]: df[(df.A == 1) & (df.D == 6)]
Out[99]:
A B C D
d 1 3 9 6
If you want to chain methods, you can add your own mask method and use that one.
In [90]: def mask(df, key, ...
How to check if all elements of a list matches a condition?
I have a list consisting of like 20000 lists. I use each list's 3rd element as a flag. I want to do some operations on this list as long as at least one element's flag is 0, it's like:
...
How to print a number with commas as thousands separators in JavaScript
... ====>"} ${x} => ${result}`);
return pass;
}
let failures = 0;
failures += !test(0, "0");
failures += !test(100, "100");
failures += !test(1000, "1,000");
failures += !test(10000, "10,000");
failures += !test(100000, "100,000");
failures += !test(1000000, "...
Ruby 2.0.0p0 IRB warning: “DL is deprecated, please use Fiddle”
...ns of Ruby, removed all of my gems
(including Rails), and installed Ruby 2.0. In other words, a totally clean re-install. Upon starting IRB, I received this message:
...
What does this square bracket and parenthesis bracket notation mean [first1,last1)?
...rst1 (and includes it), but ends just before last1.
Assuming integers:
(0, 5) = 1, 2, 3, 4
(0, 5] = 1, 2, 3, 4, 5
[0, 5) = 0, 1, 2, 3, 4
[0, 5] = 0, 1, 2, 3, 4, 5
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Javascript roundoff number to nearest 0.5
Can someone give me an idea how can i round off a number to the nearest 0.5.
I have to scale elements in a web page according to screen resolution and for that i can only assign font size in pts to 1, 1.5 or 2 and onwards etc.
...
How to check if a number is a power of 2
...his problem:
bool IsPowerOfTwo(ulong x)
{
return (x & (x - 1)) == 0;
}
Note, this function will report true for 0, which is not a power of 2. If you want to exclude that, here's how:
bool IsPowerOfTwo(ulong x)
{
return (x != 0) && ((x & (x - 1)) == 0);
}
Explanation
Fi...
What to do about Eclipse's “No repository found containing: …” error messages?
...
450
Quick answer
Go to Help → Install new software → Here uncheck “Contact all update sites d...
Linux bcc tools使用总结（持续更新） - 操作系统(内核) - 清泛网 - 专注IT技能提升
...e/bcc/tools/execsnoop -t
TIME(s) PCOMM PID PPID RET ARGS
0.996 head 12101 6578 0 /usr/bin/head -v -n 8 /proc/meminfo
0.996 head 12102 6578 0 /usr/bin/head -v -n 2 /proc/stat /proc/version /proc/uptime /proc/loadavg /proc/sys/fs/file-nr /proc/s...
Linux bcc tools使用总结（持续更新） - 操作系统(内核) - 清泛网 - 专注IT技能提升
...e/bcc/tools/execsnoop -t
TIME(s) PCOMM PID PPID RET ARGS
0.996 head 12101 6578 0 /usr/bin/head -v -n 8 /proc/meminfo
0.996 head 12102 6578 0 /usr/bin/head -v -n 2 /proc/stat /proc/version /proc/uptime /proc/loadavg /proc/sys/fs/file-nr /proc/s...