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What does $_ mean in PowerShell?
...he current value in the pipe line, which is called $PSItem in Powershell 3 and newer.
1,2,3 | %{ write-host $_ }
or
1,2,3 | %{ write-host $PSItem }
For example in the above code the %{} block is called for every value in the array. The $_ or $PSItem variable will contain the current value...
How to list all functions in a Python module?
I have a python module installed on my system and I'd like to be able to see what functions/classes/methods are available in it.
...
Where do the Python unit tests go?
...the code directory).
I prefer #1 for its simplicity of finding the tests and importing them. Whatever build system you're using can easily be configured to run files starting with test_. Actually, the default unittest pattern used for test discovery is test*.py.
...
TypeError: got multiple values for argument
I read the other threads that had to do with this error and it seems that my problem has an interesting distinct difference than all the posts I read so far, namely, all the other posts so far have the error in regards to either a user created class or a builtin system resource. I am experiencing th...
Relationship between SciPy and NumPy
...numpy as _num
from numpy import oldnumeric
from numpy import *
from numpy.random import rand, randn
from numpy.fft import fft, ifft
from numpy.lib.scimath import *
The log10 function you get in scipy comes from numpy.lib.scimath. Looking at that code, it says:
"""
Wrapper functions to more user-f...
How to apply a function to two columns of Pandas dataframe
Suppose I have a df which has columns of 'ID', 'col_1', 'col_2' . And I define a function :
12 Answers
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Is errno thread-safe?
...l
errno is defined by including the
header , as specified by the
C Standard ... For each thread of a
process, the value of errno shall not
be affected by function calls or
assignments to errno by other threads.
Also see http://linux.die.net/man/3/errno
errno is thread-local; settin...
How do I add custom field to Python log format string?
...'Super App'}
logger = logging.getLogger(__name__)
syslog = logging.StreamHandler()
formatter = logging.Formatter('%(asctime)s %(app_name)s : %(message)s')
syslog.setFormatter(formatter)
logger.setLevel(logging.INFO)
logger.addHandler(syslog)
logger = logging.LoggerAdapter(logger, extra)
logger.inf...
In which situations do we need to write the __autoreleasing ownership qualifier under ARC?
...
__autoreleasing to denote arguments that are passed by reference (id *) and are autoreleased on return.
All of this is very well explained in the ARC transition guide.
In your NSError example, the declaration means __strong, implicitly:
NSError * e = nil;
Will be transformed to:
NSError * ...
Why are Python's 'private' methods not actually private?
Python gives us the ability to create 'private' methods and variables within a class by prepending double underscores to the name, like this: __myPrivateMethod() . How, then, can one explain this
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