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What is the purpose of the word 'self'?
...way that makes the instance to which the method belongs be passed automatically, but not received automatically: the first parameter of methods is the instance the method is called on. That makes methods entirely the same as functions, and leaves the actual name to use up to you (although self is th...
How to sort a list of objects based on an attribute of the objects?
...is a need to sort by multiple fields, it could be achieved by consecutive calls to sort(), because python is using stable sort algorithm.
– zzz777
Feb 23 at 14:41
add a commen...
Python 2.7: Print to File
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In Python 3.0+, print is a function, which you'd call with print(...). In earlier version, print is a statement, which you'd make with print ....
To print to a file in Python earlier than 3.0, you'd do:
print >> f, 'what ever %d', i
The >> operator directs pr...
Access an arbitrary element in a dictionary in Python
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for a non-destructive popitem you can make a (shallow) copy: key, value = dict(d).popitem()
– Pelle
Jan 31 '18 at 10:35
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Adding a cross-reference to a subheading or anchor in another page
... because it works across files, when section headings are changed, and for all builders that support cross-references.
RST, in General
The tools that convert RST files to HTML do not necessarily have a notion of collection. This is the case for instance if you rely on github to convert RST files ...
How to get object length [duplicate]
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This is actually worse than using a simple loop and counter because of the added overhead of the callback function.
– nullability
Feb 19 '13 at 17:35
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What does `:_*` (colon underscore star) do in Scala?
...tes: MetaData, scope: NamespaceBinding,
child: Node*)
which is called as
new Elem(prefix, label, attributes, scope,
child1, child2, ... childN)
but here there is only a sequence, not child1, child2, etc. so this allows the result sequence to be used as the input to the constru...
MongoDB/NoSQL: Keeping Document Change History
... changes to one or more specific entities in a database. I've heard this called row versioning, a log table or a history table (I'm sure there are other names for it). There are a number of ways to approach it in an RDBMS--you can write all changes from all source tables to a single table (more of...
Django set default form values
...ch is explained here
You have two options either populate the value when calling form constructor:
form = JournalForm(initial={'tank': 123})
or set the value in the form definition:
tank = forms.IntegerField(widget=forms.HiddenInput(), initial=123)
...
How to tell if a tag failed to load
I'm dynamically adding <script> tags to a page's <head> , and I'd like to be able to tell whether the loading failed in some way -- a 404, a script error in the loaded script, whatever.
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