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What is the most “pythonic” way to iterate over a list in chunks?
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Finally got a chance to play around with this in a python session. For those who are as confused as I was, this is feeding the same iterator to izip_longest multiple times, causing it to consume successive values of the same seq...
python exception message capturing
...work, I get syntax error, what is the proper way of doing this for logging all kind of exceptions to a file
11 Answers
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Can I list-initialize a vector of move-only type?
...nitializer list elements in the current revision of the language.
Specifically, we have:
typedef const E& reference;
typedef const E& const_reference;
typedef const E* iterator;
typedef const E* const_iterator;
const E* begin() const noexcept; // first element
const E* end() const noexce...
Is it pythonic to import inside functions?
...at it needs to import.
If I'm adding new code to an existing file I'll usually do the import where it's needed and then if the code stays I'll make things more permanent by moving the import line to the top of the file.
One other point, I prefer to get an ImportError exception before any code is r...
Defining a variable with or without export
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Specifically export makes the variable available to child processes via the environment.
– Beano
Jul 21 '09 at 13:35
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Interfaces — What's the point?
...ntract. A set of public methods any implementing class has to have. Technically, the interface only governs syntax, i.e. what methods are there, what arguments they get and what they return. Usually they encapsulate semantics as well, although that only by documentation.
You can then have differen...
Collapse sequences of white space into a single character and trim string
...low, because it creates a new object for every substring and sends method calls to each of them.
– Georg Schölly
Jun 23 '11 at 18:55
2
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What's wrong with overridable method calls in constructors?
...ohibit it:
There are a few more restrictions that a class must obey to allow inheritance. Constructors must not invoke overridable methods, directly or indirectly. If you violate this rule, program failure will result. The superclass constructor runs before the subclass constructor, so the overr...
How to extract the n-th elements from a list of tuples?
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@Wayne Werner: Yep. This stuff was all just passive knowledge (I don't often use it) - but it's good to be reminded now and then so you know where / what to look for...
– Daren Thomas
Jul 22 '10 at 13:14
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How to 'bulk update' with Django?
...ings like incrementing rows:
from django.db.models import F
Entry.objects.all().update(n_pingbacks=F('n_pingbacks') + 1)
See the documentation.
However, note that:
This won't use ModelClass.save method (so if you have some logic inside it won't be triggered).
No django signals will be emitte...