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How to write loop in a Makefile?
...hat the seq command which generates a sequence of numbers exists on most (all?) unix systems, so you can write for number in ``seq 1 1000``; do echo $$number; done (Put a single backtick on each side of the seq command, not two, I don't know how to format this correctly using stackoverflow's syntax...
How to measure elapsed time in Python?
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If you just want to measure the elapsed wall-clock time between two points, you could use time.time():
import time
start = time.time()
print("hello")
end = time.time()
print(end - start)
This gives the execution time in seconds.
Another option since 3.3 might ...
How to set a value to a file input in HTML?
...g/drop event on other elements. See How to set file input value programatically (i.e.: when drag-dropping files)?
– Samuel Liew♦
Nov 29 '17 at 22:01
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How to attribute a single commit to multiple developers?
The way all version control systems I'm familiar with work is that each commit is attributed to a single developer. The rise of Agile Engineering, and specifically pair programming, has lead to a situation where two developers have made a significant contribution to the same task, a bug fix for exam...
What are the differences between “=” and “
... The operator <- can be used anywhere,
whereas the operator = is only allowed at the top level (e.g.,
in the complete expression typed at the command prompt) or as one
of the subexpressions in a braced list of expressions.
Let’s not put too fine a point on it: the R documentation is (su...
Compress files while reading data from STDIN
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Yes, gzip will let you do this. If you simply run gzip > foo.gz, it will compress STDIN to the file foo.gz. You can also pipe data into it, like some_command | gzip > foo.gz.
share
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What specifically are wall-clock-time, user-cpu-time, and system-cpu-time in UNIX?
I can take a guess based on the names, but what specifically are wall-clock-time, user-cpu-time, and system-cpu-time in UNIX?
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How to stop a goroutine
I have a goroutine that calls a method, and passes returned value on a channel:
6 Answers
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#if DEBUG vs. Conditional(“DEBUG”)
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It really depends on what you're going for:
#if DEBUG: The code in here won't even reach the IL on release.
[Conditional("DEBUG")]: This code will reach the IL, however calls to the method will be omitted unless DEBUG is set whe...
Pass a data.frame column name to a function
...l_name,col1,col2){
df$col_name <- df$col1 + df$col2
df
}
#Call foo() like this:
foo(dat,z,x,y)
The problem here is that df$col1 doesn't evaluate the expression col1. It simply looks for a column in df literally called col1. This behavior is described in ?Extract under the secti...