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Multiple variables in a 'with' statement?
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It is possible in Python 3 since v3.1 and Python 2.7. The new with syntax supports multiple context managers:
with A() as a, B() as b, C() as c:
doSomething(a,b,c)
Unlike the contextlib.nested, this guarantees that a and b will have their __exit__()'s cal...
Count number of records returned by group by
... needed the count of the groups I changed this to DISTINCT COUNT() OVER(), and the query performance improved dramatically.
– Joe Aldrich
Sep 20 '17 at 13:33
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Pass variables to Ruby script via command line
I've installed RubyInstaller on Windows and I'm running IMAP Sync but I need to use it to sync hundreds of accounts. If I could pass these variables to it via command line I could automate the whole process better.
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How to dynamically load a Python class
...oc.safeimport function. Here are the docs for that:
"""Import a module; handle errors; return None if the module isn't found.
If the module *is* found but an exception occurs, it's wrapped in an
ErrorDuringImport exception and reraised. Unlike __import__, if a
package path is specified, the modu...
How to document class attributes in Python? [closed]
...lightweight class whose attributes are intended to be publicly accessible, and only sometimes overridden in specific instantiations. There's no provision in the Python language for creating docstrings for class attributes, or any sort of attributes, for that matter. What is the expected and suppor...
Filtering for empty or NULL names in a queryset
...e.objects.exclude(alias__isnull=True)
If you need to exclude null values and empty strings, the preferred way to do so is to chain together the conditions like so:
Name.objects.exclude(alias__isnull=True).exclude(alias__exact='')
Chaining these methods together basically checks each condition i...
Multiprocessing vs Threading Python [duplicate]
I am trying to understand the advantages of multiprocessing over threading . I know that multiprocessing gets around the Global Interpreter Lock, but what other advantages are there, and can threading not do the same thing?
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How to automatically generate a stacktrace when my program crashes
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For Linux and I believe Mac OS X, if you're using gcc, or any compiler that uses glibc, you can use the backtrace() functions in execinfo.h to print a stacktrace and exit gracefully when you get a segmentation fault. Documentation can...
How to remove an element from a list by index
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Use del and specify the index of the element you want to delete:
>>> a = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
>>> del a[-1]
>>> a
[0, 1, 2, 3, 4, 5, 6, 7, 8]
Also supports slices:
>>> del a[2:4]
>...
What is the difference between save and insert in Mongo DB?
What is the difference between save and insert in Mongo DB?
both looks the same
9 Answers
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