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Mean per group in a data.frame [duplicate]
... the many ways to specify the variables to act on. Here, vars(-Month) says all variables except Month.
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LINQ query on a DataTable
...s.Cast<DataRow>().Where(myRow => (int)myRow["RowNo"] == 1). Personally, I don't find the call to AsEnumerable() any more complicated than the call to Cast<DataRow>(). As far as I know, the performance is the same, so it's just a matter of preference.
– Collin K
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Git Bash doesn't see my PATH
...ecutable names without extensions. In my case, I wanted to execute a file called cup.bat. In a Windows shell, typing cup would be enough. Bash doesn't work this way, it wants the full name. Typing cup.bat solved the problem. (I wasn't able to run the file though, since apparently bash couldn't under...
Doctrine - How to print out the real sql, not just the prepared statement?
...trine is not sending a "real SQL query" to the database server : it is actually using prepared statements, which means :
Sending the statement, for it to be prepared (this is what is returned by $query->getSql())
And, then, sending the parameters (returned by $query->getParameters())
and exe...
Can't open config file: /usr/local/ssl/openssl.cnf on Windows [duplicate]
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The solution is running this command:
set OPENSSL_CONF=C:\OpenSSL-Win32\bin\openssl.cfg
or
set OPENSSL_CONF=[path-to-OpenSSL-install-dir]\bin\openssl.cfg
in the command prompt before using openssl command.
Let openssl know for sure where to find its .cfg file.
Al...
Multiple ModelAdmins/views for same model in Django admin
...l may be registered only once.
class PostAdmin(admin.ModelAdmin):
list_display = ('title', 'pubdate','user')
class MyPost(Post):
class Meta:
proxy = True
class MyPostAdmin(PostAdmin):
def get_queryset(self, request):
return self.model.objects.filter(user = request.user...
Why should hash functions use a prime number modulus?
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Usually a simple hash function works by taking the "component parts" of the input (characters in the case of a string), and multiplying them by the powers of some constant, and adding them together in some integer type. So for e...
How do I read / convert an InputStream into a String in Java?
...Utils)
String result = IOUtils.toString(inputStream, StandardCharsets.UTF_8);
Using CharStreams (Guava)
String result = CharStreams.toString(new InputStreamReader(
inputStream, Charsets.UTF_8));
Using Scanner (JDK)
Scanner s = new Scanner(inputStream).useDelimiter("\\A");
String result...
URL encoding in Android
... the post :) But I am facing a problem. If the url is already encoded partially, it is encoding the already encoded parts. What should I do? For example: dj-videos.us/Music/XclusiveSinGleTrack/320%20Kbps/… The %20 is coded to %2520
– berserk
Jan 7 '14 at 7:17...
Django template how to look up a dictionary value with a variable
...I find this easier to read and it avoids the need for special coding. I usually need the key and the value inside the loop anyway.
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