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Convert a row of a data frame to vector
...u have to be careful if your row contains a factor. Here is an example:
df_1 = data.frame(V1 = factor(11:15),
V2 = 21:25)
df_1[1,] %>% as.numeric() # you expect 11 21 but it returns
[1] 1 21
Here is another example (by default data.frame() converts characters to factors)
d...
Can comments be used in JSON?
...hen it will be data too.
You could have a designated data element called "_comment" (or something) that would be ignored by apps that use the JSON data.
You would probably be better having the comment in the processes that generates/receives the JSON, as they are supposed to know what the JSON dat...
Rails Root directory path?
...
which returns a Pathname object. If you want a string you have to add .to_s. If you want another path in your Rails app, you can use join like this:
Rails.root.join('app', 'assets', 'images', 'logo.png')
In Rails 2 you can use the RAILS_ROOT constant, which is a string.
...
How to replace multiple strings in a file using PowerShell
... PowerShell to continue parsing the expression on the next line:
$original_file = 'path\filename.abc'
$destination_file = 'path\filename.abc.new'
(Get-Content $original_file) | Foreach-Object {
$_ -replace 'something1', 'something1aa' `
-replace 'something2', 'something2bb' `
-re...
Why is parenthesis in print voluntary in Python 2.7?
...*This print behavior in Python 2 can be changed to that of Python 3:
from __future__ import print_function
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Get Image size WITHOUT loading image into memory
... data (or call the load method).
Digging deeper, we see that .open calls _open which is a image-format specific overload. Each of the implementations to _open can be found in a new file, eg. .jpeg files are in JpegImagePlugin.py. Let's look at that one in depth.
Here things seem to get a bit tric...
Auto-center map with multiple markers in Google Maps API v3
...center your point:
//Example values of min & max latlng values
var lat_min = 1.3049337;
var lat_max = 1.3053515;
var lng_min = 103.2103116;
var lng_max = 103.8400188;
map.setCenter(new google.maps.LatLng(
((lat_max + lat_min) / 2.0),
((lng_max + lng_min) / 2.0)
));
map.fitBounds(new google...
How do I parallelize a simple Python loop?
...tead:
pool = multiprocessing.Pool(4)
out1, out2, out3 = zip(*pool.map(calc_stuff, range(0, 10 * offset, offset)))
Note that this won't work in the interactive interpreter.
To avoid the usual FUD around the GIL: There wouldn't be any advantage to using threads for this example anyway. You want t...
How to make the python interpreter correctly handle non-ASCII characters in string operations?
...e(u"Â ", u"") But in Python 3, just use quotes. In Python 2, you can from __future__ import unicode_literals to obtain the Python 3 behavior, but be aware this affects the entire current module.
s.replace(u"Â ", u"") will also fail if s is not a unicode string.
string.replace returns a new string ...
使用std::string作为std::map的key出错解决 - C/C++ - 清泛网 - 专注C/C++及内核技术
...0\vc\include\xstddef(180): error C2784: “bool std::operator <(const std::_Tree<_Traits> &,const std::_Tree<_Traits> &)”: 未能从“const std::string”为“const std::_Tree<_Traits> &”推导 模板 参数
1> c:\program files (x86)\microsoft visual studio 11.0\vc\include\xtree(2245...