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Check existence of input argument in a Bash shell script
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I like to do it this way, in terse syntax and still POSIX acceptable. [ -z "$1" ] && echo "No argument supplied" I prefer one-liners, as they are easier for me; and it's also faster to check exit value, compared to using if
– J. M. Beck...
What are C++ functors and their uses?
...about functors in C++. Can someone give me an overview as to what they are and in what cases they would be useful?
14 Answe...
Difference between “and” and && in Ruby?
What is the difference between the && and and operators in Ruby?
7 Answers
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Android Studio Stuck at Gradle Download on create new project
I have installed the new Android Studio . Everything was working fine but when I try to create a new project it gets stuck at downloading Gradle .
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Label encoding across multiple columns in scikit-learn
I'm trying to use scikit-learn's LabelEncoder to encode a pandas DataFrame of string labels. As the dataframe has many (50+) columns, I want to avoid creating a LabelEncoder object for each column; I'd rather just have one big LabelEncoder objects that works across all my columns of data. ...
Confusion between factor levels and factor labels
There seems to be a difference between levels and labels of a factor in R.
Up to now, I always thought that levels were the 'real' name of factor levels, and labels were the names used for output (such as tables and plots). Obviously, this is not the case, as the following example shows:
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Retina displays, high-res background images
...wer, here is the retina detection query I tend to use:
@media
only screen and (-webkit-min-device-pixel-ratio: 2),
only screen and ( min--moz-device-pixel-ratio: 2),
only screen and ( -o-min-device-pixel-ratio: 2/1),
only screen and ( min-device-pixel-ratio: 2),
only screen and ( ...
Getting the last element of a list
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some_list[-1] is the shortest and most Pythonic.
In fact, you can do much more with this syntax. The some_list[-n] syntax gets the nth-to-last element. So some_list[-1] gets the last element, some_list[-2] gets the second to last, etc, all the way down t...
What is the rationale for fread/fwrite taking size and count as arguments?
We had a discussion here at work regarding why fread and fwrite take a size per member and count and return the number of members read/written rather than just taking a buffer and size. The only use for it we could come up with is if you want to read/write an array of structs which aren't evenly div...
What is the difference between range and xrange functions in Python 2.X?
Apparently xrange is faster but I have no idea why it's faster (and no proof besides the anecdotal so far that it is faster) or what besides that is different about
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