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Undocumented NSURLErrorDomain error codes (-1001, -1003 and -1004) using StoreKit
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All error codes are on "CFNetwork Errors Codes References" on the documentation (link)
A small extraction for CFURL and CFURLConnection Errors:
kCFURLErrorUnknown = -998,
kCFURLErrorCancelled = -999,
kCFURLErrorBadU...
Serializing class instance to JSON
...ps() only knows how to serialize a limited set of object types by default, all built-in types. List here: https://docs.python.org/3.3/library/json.html#encoders-and-decoders
One good solution would be to make your class inherit from JSONEncoder and then implement the JSONEncoder.default() function...
Assigning a variable NaN in python without numpy
...aking) be said to be equal to one another -- see What is the rationale for all comparisons returning false for IEEE754 NaN values? for more details and information.
Instead, use math.isnan(...) if you need to determine if a value is NaN or not.
Furthermore, the exact semantics of the == operation...
How to Batch Rename Files in a macOS Terminal?
...g).
If you find yourself batch-renaming files frequently, consider installing a specialized tool such as the Perl-based rename utility.
On macOS you can install it using popular package manager Homebrew as follows:
brew install rename
Here's the equivalent of the command at the top using rena...
Finding the source code for built-in Python functions?
...out what file a particular module or function is implemented in you can usually print the __file__ attribute. Alternatively, you may use the inspect module, see the section Retrieving Source Code in the documentation of inspect.
For built-in classes and methods this is not so straightforward since ...
Tree data structure in C#
...e so many ways you could implement it that it would be impossible to cover all bases with one solution. The more specific a solution, the less likely it is applicable to any given problem. I even get annoyed with LinkedList - what if I want a circular linked list?
The basic structure you'll need ...
Two way/reverse map [duplicate]
...
1
>>> del d['foo']
>>> d['bar']
Traceback (most recent call last):
File "<stdin>", line 7, in <module>
KeyError: 'bar'
I'm sure I didn't cover all the cases, but that should get you started.
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multiprocessing.Pool: When to use apply, apply_async or map?
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Back in the old days of Python, to call a function with arbitrary arguments, you would use apply:
apply(f,args,kwargs)
apply still exists in Python2.7 though not in Python3, and is generally not used anymore. Nowadays,
f(*args,**kwargs)
is preferred. The...
static constructors in C++? I need to initialize private static objects
... to have a class with a private static data member (a vector that contains all the characters a-z). In java or C#, I can just make a "static constructor" that will run before I make any instances of the class, and sets up the static data members of the class. It only gets run once (as the variables ...
Writing unit tests in Python: How do I start? [closed]
.... It is standard which means that it's kind of guaranteed to work well. Finally, anyone who uses your code doesn't need to install extra packages.
– Jeyekomon
Jul 6 '18 at 15:04
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