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Understanding Python's “is” operator
What does it really mean?
11 Answers
11
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Dynamic constant assignment
...ject itself is different each time the method is called. For example:
def foo
p "bar".object_id
end
foo #=> 15779172
foo #=> 15779112
Perhaps if you explained your use case—why you want to change the value of a constant in a method—we could help you with a better implementation.
Per...
How to get the filename without the extension in Java?
...me, would rather use some library code where they probably have thought of all special cases, such as what happens if you pass in null or dots in the path but not in the filename, you can use the following:
import org.apache.commons.io.FilenameUtils;
String fileNameWithOutExt = FilenameUtils.remove...
What's a concise way to check that environment variables are set in a Unix shell script?
...is therefore in the Korn Shell, and in the POSIX shells, including specifically Bash.
It is usually documented in the shell's man page in a section called Parameter Expansion. For example, the bash manual says:
${parameter:?word}
Display Error if Null or Unset. If parameter is null or unset, the...
How do I declare an array of weak references in Swift?
...e
}
}
And then using these in the array
var weakThings = WeakThing<Foo>[]()
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SyntaxError: Non-ASCII character '\xa3' in file when function returns '£'
... First line is to make the py file executable on *nix. It is not really related to this question.
– cmd
Dec 15 '17 at 20:21
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Checking for a dirty index or untracked files with Git
...din, command line options, arguments, etc. will produce the same output in all versions of Git where the command/option exists). New output variations in plumbing commands can be introduced via new options, but that can not introduce any problems for programs that have already been written against o...
How do I install Python OpenCV through Conda?
I'm trying to install OpenCV for Python through Anaconda , but I can't seem to figure this out.
41 Answers
...
Convert Go map to json
...arshal(datas)
fmt.Println(err)
// [] json: unsupported type: map[int]main.Foo
The thing is you cannot use integers as keys in JSON; it is forbidden. Instead, you can convert these values to strings beforehand, for instance using strconv.Itoa.
See this post for more details: https://stackoverflow...
How do you use the Immediate Window in Visual Studio?
...r example, let’s say this is what your class looks like:
private class Foo
{
public string GetMessage()
{
return "hello";
}
}
If the object already exists in memory and it’s in scope, then you can call it in the Immediate Window as long as it has been instantiated before ...