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Why dict.get(key) instead of dict[key]?
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It allows you to provide a default value if the key is missing:
dictionary.get("bogus", default_value)
returns default_value (whatever you choose it to be), whereas
dictionary["bogus"]
would raise a KeyError.
If omitted...
Maven2: Best practice for Enterprise Project (EAR file)
...ur two dependencies for your EJB project and your WAR project.
So you actually have three maven projects here. One EJB. One WAR. One EAR that pulls the two parts together and creates the ear.
Deployment descriptors can be generated by maven, or placed inside the resources directory in the EAR pr...
How to reference a file for variables using Bash?
I want to call a settings file for a variable, how can I do this in bash?
9 Answers
9
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what is reverse() in Django
...!-- django <= 1.4 -->
<a href="{% url url_name %}">link which calls some_view</a>
<!-- django >= 1.5 or with {% load url from future %} in your template -->
<a href="{% url 'url_name' %}">link which calls some_view</a>
This will be rendered as:
<a href="...
How to change the type of a field?
...(x)) and then save the document again.
If you need to do this programmatically and entirely from the shell, you can use the find(...).forEach(function(x) {}) syntax.
In response to the second comment below. Change the field bad from a number to a string in collection foo.
db.foo.find( { 'bad' :...
How to access the correct `this` inside a callback?
...d inside each function and its value only depends on how the function was called, not how/when/where it was defined. It is not affected by lexical scopes like other variables (except for arrow functions, see below). Here are some examples:
function foo() {
console.log(this);
}
// normal functio...
Why split the tag when writing it with document.write()?
...lt;script> and/or </script> tags up within document.write() calls?
5 Answers
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How to get the primary IP address of the local machine on Linux and OS X? [closed]
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You can alias the command in your .bashrc to create your own command called myip for instance.
alias myip="ifconfig | sed -En 's/127.0.0.1//;s/.*inet (addr:)?(([0-9]*\.){3}[0-9]*).*/\2/p'"
A much simpler way is hostname -I (hostname -i for older versions of hostname but see comments). However...
Java: Calling a super method which calls an overridden method
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The keyword super doesn't "stick". Every method call is handled individually, so even if you got to SuperClass.method1() by calling super, that doesn't influence any other method call that you might make in the future.
That means there is no direct way to call SuperClass.m...
Can PostgreSQL index array columns?
... to this question in the documentation. If a column is an array type, will all the entered values be individually indexed?
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