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Printf width specifier to maintain precision of floating-point value
...be to print one seventh as in:
#include <float.h>
int Digs = DECIMAL_DIG;
double OneSeventh = 1.0/7.0;
printf("%.*e\n", Digs, OneSeventh);
// 1.428571428571428492127e-01
But let's dig deeper ...
Mathematically, the answer is "0.142857 142857 142857 ...", but we are using finite precision...
Finding the index of an item in a list
...atch, you can give index a hint. For instance, in this snippet, l.index(999_999, 999_990, 1_000_000) is roughly five orders of magnitude faster than straight l.index(999_999), because the former only has to search 10 entries, while the latter searches a million:
>>> import timeit
>>&g...
Is cout synchronized/thread-safe?
... @ildjarn - No, @edA-qa mort-ora-y is correct. As long as cout.sync_with_stdio() is true, using cout to output characters from multiple threads without additional synchronization is well-defined, but only on the level of individual bytes. Thus, cout << "ab"; and cout << "cd" exec...
Fastest way to get the first object from a queryset in django?
...ust do the above and it will only pull the first. You could even use .order_by() to ensure you get the first you want.
Be sure to add the .get() or else you will get a QuerySet back and not an object.
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Convert a Scala list to a tuple?
... I know of, but it's easy enough to make your own, e.g. case class Vec3[A](_1: A, _2: A, _3: A)
– Tom Crockett
Sep 16 '14 at 6:43
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Find out how much memory is being used by an object in Python [duplicate]
...
Try this:
sys.getsizeof(object)
getsizeof() calls the object’s __sizeof__ method and adds an additional garbage collector overhead if the object is managed by the garbage collector.
A recursive recipe
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logger configuration to log to file and print to stdout
... you are trying to see info or debug messages
– storm_m2138
Mar 28 '18 at 23:06
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How disable Copy, Cut, Select, Select All in UITextView
... your /, file where you need this behaviour.
– markus_p
Apr 3 '12 at 10:07
4
This only works as a...
How to access app.config in a blueprint?
...horisation.py which in a package api. I am initializing the blueprint in __init__.py which is used in authorisation.py .
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How to use PyCharm to debug Scrapy projects
... a virtualenv with Python 3.5.0 and setting the "script" parameter to /path_to_project_env/env/bin/scrapy solved the issue for me.
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