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What are all the uses of an underscore in Scala?
...ang.org and noticed a curious question: " Can you name all the uses of “_”? ". Can you? If yes, please do so here. Explanatory examples are appreciated.
...
How to get the parent dir location
...bspath doesn't validate anything, so if we're already appending strings to __file__ there's no need to bother with dirname or joining or any of that. Just treat __file__ as a directory and start climbing:
# climb to __file__'s parent's parent:
os.path.abspath(__file__ + "/../../")
That's far less...
How do I get the opposite (negation) of a Boolean in Python?
... function
There are also two functions in the operator module operator.not_ and it's alias operator.__not__ in case you need it as function instead of as operator:
>>> import operator
>>> operator.not_(False)
True
>>> operator.not_(True)
False
These can be useful if yo...
Python hashable dicts
...another dictionary for obvious reasons.
class hashabledict(dict):
def __hash__(self):
return hash(tuple(sorted(self.items())))
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Ruby: Can I write multi-line string with no concatenation?
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p <<END_SQL.gsub(/\s+/, " ").strip
SELECT * FROM users
ORDER BY users.id DESC
END_SQL
# >> "SELECT * FROM users ORDER BY users.id DESC"
The latter would mostly be for situations that required more flexibility in the processing. I personally don't like it, it puts the proc...
Why is __dirname not defined in node REPL?
From the node manual I see that I can get the directory of a file with __dirname , but from the REPL this seems to be undefined. Is this a misunderstanding on my side or where is the error?
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What is a “Bitmap heap scan” in a query plan?
... is different from an index scan, where the index is visited row by row in order -- meaning a disk page may get visited multiple times.
Re: the question in your comment... Yep, that's exactly it.
An index scan will go through rows one by one, opening disk pages again and again, as many times as ...
Multiple levels of 'collection.defaultdict' in Python
... @ScienceFriction Anything specific that you need help with? When d[new_key] is accessed, it will call the lambda which will create a new defaultdict(int). And when d[existing_key][new_key2] is accessed, a new int will be created.
– interjay
Oct 11 '13 at 1...
Python - Get path of root project structure
...tils.py
In definitions.py you can define (this requires import os):
ROOT_DIR = os.path.dirname(os.path.abspath(__file__)) # This is your Project Root
Thus, with the Project Root known, you can create a variable that points to the location of the configuration (this can be defined anywhere, but ...
Dictionary vs Object - which is more efficient and why?
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Have you tried using __slots__?
From the documentation:
By default, instances of both old and new-style classes have a dictionary for attribute storage. This wastes space for objects having very few instance variables. The space consumption can ...