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'is' versus try cast with null check
...ersion is not thread-safe. The value of myObj or myProp could get changed (by another thread) between the is and the cast, causing undesirable behaviour.
– Jeff
Nov 15 '12 at 21:16
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Entity Framework 4 Single() vs First() vs FirstOrDefault()
...turned by a query but you only want to access the first item in your code (ordering could be important in the query here). This will throw an exception if the query does not return at least one item.
FirstOrDefault() - when you expect zero or more items to be returned by a query but you only want to...
Updating MySQL primary key
..., user_1, type, max(timestamp), count(*) n from user_interactions u
group by user_2, user_1, type
having n > 1;
delete u from user_interactions u, fixit
where fixit.user_2 = u.user_2
and fixit.user_1 = u.user_1
and fixit.type = u.type
and fixit.timestamp != u.timestamp;
alter table u...
Why does Eclipse automatically add appcompat v7 library support whenever I create a new project?
Why does Eclipse automatically add appcompat v7 library support whenever I create a new project?
10 Answers
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Check existence of input argument in a Bash shell script
...ally ignores the arguments it is provided. It is essential in this test in order to keep the interpreter from trying to execute the contents of "$varname" (which you certainly do NOT want to happen). Also worth noting; you can test as many variables with this method as you wish. And all with specifi...
Print in one line dynamically
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FYI: print(item, end=" ") can be used in Python2.7 by adding 'from future import print_function' at top of file.
– Hec
Aug 24 '16 at 21:29
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How to efficiently build a tree from a flat structure?
...ntID property so they can be arranged in trees. They are in no particular order.
Each ParentID property does not necessarily matches with an ID in the structure. Therefore their could be several trees emerging from these objects.
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Python decorators in classes
...orator in some debugging situations, it allows overriding class properties by decorating, without having to find the calling function.
class myclass(object):
def __init__(self):
self.property = "HELLO"
@adecorator(property="GOODBYE")
def method(self):
print self.propert...
How to refer to relative paths of resources when working with a code repository
...n't work inside a package, just from the same dir (or the working dir) set by the script.
– alexandra
Apr 25 '19 at 13:09
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Starting python debugger automatically on error
...en it will run to the error point and give you control there. As mentioned by eqzx, this flag is a new addition in python 3.2 so entering 'c' is required for earlier Python versions (see https://docs.python.org/3/library/pdb.html).
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