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How do I avoid capturing self in blocks when implementing an API?
I have a working app and I'm working on converting it to ARC in Xcode 4.2. One of the pre-check warnings involves capturing self strongly in a block leading to a retain cycle. I've made a simple code sample to illustrate the issue. I believe I understand what this means but I'm not sure the "corre...
What is the best way to implement nested dictionaries?
...data structure which essentially amounts to a nested dictionary. Let's say it looks like this:
21 Answers
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Are there legitimate uses for JavaScript's “with” statement?
Alan Storm's comments in response to my answer regarding the with statement got me thinking. I've seldom found a reason to use this particular language feature, and had never given much thought to how it might cause trouble. Now, I'm curious as to how I might make effective use of with , while a...
How do I add custom field to Python log format string?
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You could use a LoggerAdapter so you don't have to pass the extra info with every logging call:
import logging
extra = {'app_name':'Super App'}
logger = logging.getLogger(__name__)
syslog = logging.StreamHandler()
formatter = logging.Formatter('%(asctime)s %(app_name)s : %(message)s')
syslog.se...
What's the difference between globals(), locals(), and vars()?
...als() always returns a dictionary of the current namespace
vars() returns either a dictionary of the current namespace (if called with no argument) or the dictionary of the argument.
locals and vars could use some more explanation. If locals() is called inside a function, it updates a dict with t...
How do you calculate the average of a set of circular data? [closed]
...mples from the reading of a compass. The problem of course is how to deal with the wraparound. The same algorithm might be useful for a clockface.
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Convert sqlalchemy row object to python dict
Is there a simple way to iterate over column name and value pairs?
36 Answers
36
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Django 1.7 - makemigrations not detecting changes
As the title says, I can't seem to get migrations working.
29 Answers
29
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Event system in Python
...2.1.2: 2017
axel 0.0.7: 2016
blinker 1.4: 2015
PyDispatcher 2.0.5: 2015
pymitter 0.2.3: 2014
dispatcher 1.0: 2012
py-notify 0.3.1: 2008
There's more
That's a lot of libraries to choose from, using very different terminology (events, signals, handlers, method dispatch, hooks, ...).
I'm trying to kee...
Count number of records returned by group by
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This down side of this solution is that it gives you the answer multiple times (for each combination of column_1, column_2, column_3, column_4). This may or may not be a significant side-effect, depending on how you process the results.
– car...