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Shards and replicas in Elasticsearch
... elasticsearch will create 5 primary shards that will contain your data:
____ ____ ____ ____ ____
| 1 | | 2 | | 3 | | 4 | | 5 |
|____| |____| |____| |____| |____|
Every time you index a document, elasticsearch will decide which primary shard is supposed to hold that docu...
Iterate over object attributes in python
... object attributes are callable, such as methods.
>>> dir(obj)
['__class__', '__delattr__', '__dict__', '__doc__', '__format__', '__getattribute__', '__hash__', '__init__', '__module__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__sizeof__', '__str__', '__subcla...
What are “first class” objects?
...ally has a fairly rich and sophisticated interface.
>>> dir(2)
['__abs__', '__add__', '__and__', '__class__', '__cmp__', '__coerce__', '__delattr__', '__div__', '__divmod__', '__doc__', '__float__', '__floordiv__', '__getattribute__', '__getnewargs__', '__hash__', '__hex__', '__index__', '...
Build a Basic Python Iterator
... to the iterator protocol, which basically means they provide two methods: __iter__() and __next__().
The __iter__ returns the iterator object and is implicitly called
at the start of loops.
The __next__() method returns the next value and is implicitly called at each loop increment. This met...
Difference between left join and right join in SQL Server [duplicate]
... two table with following records:
Table A
id firstname lastname
___________________________
1 Ram Thapa
2 sam Koirala
3 abc xyz
6 sruthy abc
Table B
id2 place
_____________
1 Nepal
2 USA
3 Lumbini
5 Kathmandu
Inne...
How to implement __iter__(self) for a container object (Python)
...owing will create an iterator that yields five, and then every item in some_list.
def __iter__(self):
yield 5
yield from some_list
Pre-3.3, yield from didn't exist, so you would have to do:
def __iter__(self):
yield 5
for x in some_list:
yield x
...
Python dictionary from an object's fields
...s'. To build a dictionary from an arbitrary object, it's sufficient to use __dict__. Usually, you'll declare your methods at class level and your attributes at instance level, so __dict__ should be fine. For example:
>>> class A(object):
... def __init__(self):
... self.b = 1
... ...
Multi-line string with extra space (preserved indentation)
...o use a helper function and some variable substitution tricks:
unset text
_() { text="${text}${text+
}${*}"; }
# That's an empty line which demonstrates the reasoning behind
# the usage of "+" instead of ":+" in the variable substitution
# above.
_ ""
_ "this is line one"
_ "this is line two"
_ "...
Python extending with - using super() Python 3 vs Python 2
...
super() (without arguments) was introduced in Python 3 (along with __class__):
super() -> same as super(__class__, self)
so that would be the Python 2 equivalent for new-style classes:
super(CurrentClass, self)
for old-style classes you can always use:
class Classname(OldStyleParen...
How do I correctly clean up a Python object?
__del__(self) above fails with an AttributeError exception. I understand Python doesn't guarantee the existence of "global variables" (member data in this context?) when __del__() is invoked. If that is the case and this is the reason for the exception, how do I make sure the object destructs...