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Learning Python from Ruby; Differences and Similarities
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[x*x for x in values if x > 15]
to get a new list of the squares of all values greater than 15. In Ruby, you'd have to write the following:
values.select {|v| v > 15}.map {|v| v * v}
The Ruby code doesn't feel as compact. It's also not as efficient since it first converts the values a...
iOS JavaScript bridge
...t's something simple enough that you might give it a try yourself. I personally did exactly this when I needed to do that. You might also create a simple library that suits your needs.
1. Execute JS methods from Objective-C
This is really just one line of code.
NSString *returnvalue = [webView st...
JavaScript equivalent to printf/String.Format
...low for details.
Otherwise:
Try sprintf() for JavaScript.
If you really want to do a simple format method on your own, don’t do the replacements successively but do them simultaneously.
Because most of the other proposals that are mentioned fail when a replace string of previous replaceme...
Django: Why do some model fields clash with each other?
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You have two foreign keys to User. Django automatically creates a reverse relation from User back to GameClaim, which is usually gameclaim_set. However, because you have two FKs, you would have two gameclaim_set attributes, which is obviously impossible. So you need to tell D...
What's the pythonic way to use getters and setters?
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print("deleter of x called")
del self._x
c = C()
c.x = 'foo' # setter called
foo = c.x # getter called
del c.x # deleter called
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pandas GroupBy columns with NaN (missing) values
...n the Missing Data section of the docs:
NA groups in GroupBy are automatically excluded. This behavior is consistent with R, for example.
One workaround is to use a placeholder before doing the groupby (e.g. -1):
In [11]: df.fillna(-1)
Out[11]:
a b
0 1 4
1 2 -1
2 3 6
In [12]: df.fil...
Authoritative position of duplicate HTTP GET query keys
...t you like.
Typical approaches include: first-given, last-given, array-of-all, string-join-with-comma-of-all.
Suppose the raw request is:
GET /blog/posts?tag=ruby&tag=rails HTTP/1.1
Host: example.com
Then there are various options for what request.query['tag'] should yield, depending on the...
How to use SSH to run a local shell script on a remote machine?
...ssh user@host2 <<'END2'
# Another bunch of commands on another host
wall <<'ENDWALL'
Error: Out of cheese
ENDWALL
ftp ftp.secureftp-test.com <<'ENDFTP'
test
test
ls
ENDFTP
END2
ENDSSH
You can actually have a conversation with some services like telnet, ftp, etc. But remember that...
How do I pass multiple parameters into a function in PowerShell?
...h accepts more than one string parameter, the first parameter seems to get all the data assigned to it, and remaining parameters are passed in as empty.
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Execute a terminal command from a Cocoa app
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NSFileHandle *file = pipe.fileHandleForReading;
NSTask *task = [[NSTask alloc] init];
task.launchPath = @"/usr/bin/grep";
task.arguments = @[@"foo", @"bar.txt"];
task.standardOutput = pipe;
[task launch];
NSData *data = [file readDataToEndOfFile];
[file closeFile];
NSString *grepOutput = [[NSS...