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What is the most efficient/elegant way to parse a flat table into a tree?
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Now that MySQL 8.0 supports recursive queries, we can say that all popular SQL databases support recursive queries in standard syntax.
WITH RECURSIVE MyTree AS (
SELECT * FROM MyTable WHERE ParentId IS NULL
UNION ALL
SELECT m.* FROM MyTABLE AS m JOIN MyTree AS t ON m.ParentI...
How do I write good/correct package __init__.py files
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__all__ is very good - it helps guide import statements without automatically importing modules
http://docs.python.org/tutorial/modules.html#importing-from-a-package
using __all__ and import * is redundant, only __all__ is nee...
A simple explanation of Naive Bayes Classification
... & part two being the confusion surrounding Training set.
In general all of Machine Learning Algorithms need to be trained for supervised learning tasks like classification, prediction etc. or for unsupervised learning tasks like clustering.
During the training step, the algorithms are taught...
List all the modules that are part of a python package?
Is there a straightforward way to find all the modules that are part of a python package? I've found this old discussion , which is not really conclusive, but I'd love to have a definite answer before I roll out my own solution based on os.listdir().
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List all indexes on ElasticSearch server?
I would like to list all indexes present on an ElasticSearch server. I tried this:
22 Answers
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Dictionary vs Object - which is more efficient and why?
...ots__ = ('i', 'l')
def __init__(self, i):
self.i = i
self.l = []
all = {}
for i in range(1000000):
all[i] = Obj(i)
test_obj.py:
class Obj(object):
def __init__(self, i):
self.i = i
self.l = []
all = {}
for i in range(1000000):
all[i] = Obj(i)
test_dict.py:
all = {}
for i in...
List all the files that ever existed in a Git repository
Do you have a clean way to list all the files that ever existed in specified branch?
4 Answers
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In Bash, how do I add a string after each line in a file?
... answered May 13 at 11:59
欢乐的Xiaox欢乐的Xiaox
6944 bronze badges
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What are all the uses of an underscore in Scala?
...s taken on scala-lang.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.
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Class with Object as a parameter
... Table to be a new-style class (as opposed to "classic" class).
In Python3 all classes are new-style classes, so this is no longer necessary.
New style classes have a few special attributes that classic classes lack.
class Classic: pass
class NewStyle(object): pass
print(dir(Classic))
# ['__doc__...