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Update MongoDB field using value of another field
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The best way to do this is in version 4.2+ which allows using of aggregation pipeline in the update document and the updateOne, updateMany or update collection method. Note that the latter has been deprecated in most if not all languages drivers.
MongoDB 4.2+
Version 4.2 ...
Is “else if” a single keyword?
...er to Can you start a class name with a numeric digit? that spaces are not allowed in identifiers and so therefore else if can not be a single keyword but must be two separate keywords.
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How to count the number of set bits in a 32-bit integer?
...Hamming Weight', 'popcount' or 'sideways addition'.
The 'best' algorithm really depends on which CPU you are on and what your usage pattern is.
Some CPUs have a single built-in instruction to do it and others have parallel instructions which act on bit vectors. The parallel instructions (like x86's ...
How to find out if you're using HTTPS without $_SERVER['HTTPS']
...PHP as a Fast-CGI application).
Also, Apache 1.x servers (and broken installations) might not have $_SERVER['HTTPS'] defined even if connecting securely. Although not guaranteed, connections on port 443 are, by convention, likely using secure sockets, hence the additional port check.
Additional n...
Rename multiple files in a directory in Python [duplicate]
...e script itself. Instead of using . as the dir, you could make a variable called dir and use that, then prepend dir to the filename.
– styfle
May 18 '11 at 5:53
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Python division
...-100 and was having problems only to notice that even with no variables at all, this does not evaluate the way I would expect it to:
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What does “program to interfaces, not implementations” mean?
...t worried about implementation and the interface signature determines what all operations can be done. This can be used to change the behavior of a program at run-time. It also helps you to write far better programs from the maintenance point of view.
Here's a basic example for you.
public enum La...
How to run functions in parallel?
...find an answer to my question. I am trying to run multiple functions in parallel in Python.
6 Answers
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Length of generator output [duplicate]
... Fibonacci numbers. You can get as many Fibonacci numbers as you want by calling next().
If you really need to know the number of items there are, then you can't iterate through them linearly one time anyway, so just use a different data structure such as a regular list.
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How do I add custom field to Python log format string?
...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.setFormatter(formatte...