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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...
Why is lazy evaluation useful?
...zy language. Strictness also exacerbates the fact that where has no way to order the relative effects at all, except by SCC, it is a statement level construction, its effects could happen in any order strictly, and even if you have a pure language you wind up with the #f issue. Strict where riddles ...
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"
_ "...
UDP vs TCP, how much faster is it? [closed]
...le much more efficiently than TCP's point-to-point acknowledgement.
Out-of-order delivery: in lots of applications, as long as you get all the data, you don't care what order it arrives in; you can reduce app-level latency by accepting an out-of-order block.
Unfriendliness: on a LAN party, you may ...
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...
What does it mean: The serializable class does not declare a static final serialVersionUID field? [d
... the serialization
(additional fields, removed fields,
change of field order, ...)
That's not correct, and you will be unable to cite an authoriitative source for that claim. It should be changed whenever you make a change that is incompatible under the rules given in the Versioning of Seriali...
Python - List of unique dictionaries
...
note that this may alter the order of the dictionaries in the list! use OrderedDict from collections list(OrderedDict((v['id'], v) for v in L).values()) or sort the resulting list if that works better for you
– gevra
...
How do I check OS with a preprocessor directive?
...ecks. Here are a few of them, with links to where they're found:
Windows
_WIN32 Both 32 bit and 64 bit
_WIN64 64 bit only
Unix (Linux, *BSD, Mac OS X)
See this related question on some of the pitfalls of using this check.
unix
__unix
__unix__
Mac OS X
__APPLE__
__MACH__
Both are de...
what does the __file__ variable mean/do?
...
When a module is loaded from a file in Python, __file__ is set to its path. You can then use that with other functions to find the directory that the file is located in.
Taking your examples one at a time:
A = os.path.join(os.path.dirname(__file__), '..')
# A is the par...