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Behaviour of increment and decrement operators in Python
...so far as they don't explain what happens.
To be exact, +x evaluates to x.__pos__() and ++x to x.__pos__().__pos__().
I could imagine a VERY weird class structure (Children, don't do this at home!) like this:
class ValueKeeper(object):
def __init__(self, value): self.value = value
def __s...
How to deal with SettingWithCopyWarning in Pandas?
...H5390 and GH5597 for background discussion.]
df[df['A'] > 2]['B'] = new_val # new_val not set in df
The warning offers a suggestion to rewrite as follows:
df.loc[df['A'] > 2, 'B'] = new_val
However, this doesn't fit your usage, which is equivalent to:
df = df[df['A'] > 2]
df['B'] = ...
Calling a function of a module by using its name (a string)
...
Assuming module foo with method bar:
import foo
method_to_call = getattr(foo, 'bar')
result = method_to_call()
You could shorten lines 2 and 3 to:
result = getattr(foo, 'bar')()
if that makes more sense for your use case.
You can use getattr in this fashion on class insta...
Should I use Vagrant or Docker for creating an isolated environment? [closed]
... application in a wide variety of envionment configs (different databases, php versions, caching backends etc), then I can easily do that with docker containers. But I cant see if my application will run properly in a windows IIS env, or on BSD or OSX.
– Mixologic
...
error LNK2019: unresolved external symbol _WinMain@16 referenced in function ___tmainCRTStartup
...you can just hint at what your entry point is, because you haven't defined ___tmainCRTStartup. You can do this by adding the following to Properties -> Linker -> Command line:
/ENTRY:"mainCRTStartup"
This way you get rid of the console window.
...
Short description of the scoping rules?
...ithout explicit declaration, but writing to it without declaring global(var_name) will instead create a new local instance.
– Peter Gibson
Jun 27 '12 at 5:53
12
...
What is the formal difference in Scala between braces and parentheses, and when should they be used?
...e method expects a single parameter. For example:
List(1, 2, 3).reduceLeft{_ + _} // valid, single Function2[Int,Int] parameter
List{1, 2, 3}.reduceLeft(_ + _) // invalid, A* vararg parameter
However, there’s more you need to know to better grasp these rules.
Increased compile checking with pare...
Stop Mongoose from creating _id property for sub-document array items
...ose");
var subSchema = mongoose.Schema({
//your subschema content
},{ _id : false });
var schema = mongoose.Schema({
// schema content
subSchemaCollection : [subSchema]
});
var model = mongoose.model('tablename', schema);
...
How to add a custom loglevel to Python's logging facility
... example that checks if the logging level is enabled:
import logging
DEBUG_LEVELV_NUM = 9
logging.addLevelName(DEBUG_LEVELV_NUM, "DEBUGV")
def debugv(self, message, *args, **kws):
if self.isEnabledFor(DEBUG_LEVELV_NUM):
# Yes, logger takes its '*args' as 'args'.
self._log(DEBUG...
How to perform OR condition in django queryset?
...
from django.db.models import Q
User.objects.filter(Q(income__gte=5000) | Q(income__isnull=True))
via Documentation
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