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Should __init__() call the parent class's __init__()?
...
In Python, calling the super-class' __init__ is optional. If you call it, it is then also optional whether to use the super identifier, or whether to explicitly name the super class:
object.__init__(self)
In case of object, calling th...
How does python numpy.where() work?
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How do they achieve internally that you are able to pass something like x > 5 into a method?
The short answer is that they don't.
Any sort of logical operation on a numpy array returns a boolean array. (i.e. __gt__, __lt__, etc all return boolea...
How to remove all of the data in a table using Django
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Inside a manager:
def delete_everything(self):
Reporter.objects.all().delete()
def drop_table(self):
cursor = connection.cursor()
table_name = self.model._meta.db_table
sql = "DROP TABLE %s;" % (table_name, )
cursor.execute(sql)
...
Why use Abstract Base Classes in Python?
...emented classes.
Long version
There is a contract between a class and its callers. The class promises to do certain things and have certain properties.
There are different levels to the contract.
At a very low level, the contract might include the name of a method or its number of parameters.
In a s...
__FILE__ macro shows full path
....com/pipermail/cmake/2013-January/053117.html
I'm copying the tip so it's all on this page:
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -D__FILENAME__='\"$(subst
${CMAKE_SOURCE_DIR}/,,$(abspath $<))\"'")
If you're using GNU make, I see no reason you couldn't extend this to your own makefiles. ...
How can I swap positions of two open files (in splits) in vim?
... 'hide buf' markedBuf
endfunction
nmap <silent> <leader>mw :call MarkWindowSwap()<CR>
nmap <silent> <leader>pw :call DoWindowSwap()<CR>
To use (assuming your mapleader is set to \) you would:
Move to the window to mark for the swap via
ctrl-w movement
Type ...
A python class that acts like dict
...er) instead of simply delegating to the instance's __dict__ - which essentially means you're creating two dicts for every instance.
– Aaron Hall♦
Jan 8 '17 at 0:39
8
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Why does this loop produce “warning: iteration 3u invokes undefined behavior” and output more than 4
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If during the evaluation of an expression, the result is not mathematically defined or not in the range of
representable values for its type, the behavior is undefined. [ Note: most existing implementations of C++
ignore integer overflows. Treatment of division by zero, forming a remainde...
Byte order mark screws up file reading in Java
...va. Some of the files may have a byte order mark in the beginning, but not all. When present, the byte order gets read along with the rest of the first line, thus causing problems with string compares.
...
“Notice: Undefined variable”, “Notice: Undefined index”, and “Notice: Undefined offset” using PHP
... can be used to detect if a variable has been already initialized. Additionally and more ideal is the solution of empty() since it does not generate a warning or error message if the variable is not initialized.
From PHP documentation:
No warning is generated if the variable does not exist. T...