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Is it possible to use 'else' in a list comprehension? [duplicate]
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The syntax a if b else c is a ternary operator in Python that evaluates to a if the condition b is true - otherwise, it evaluates to c. It can be used in comprehension statements:
>>> [a if a else 2 for a in [0,1,0,3]]
[2, 1, 2,...
What is the correct way to get a subarray in Scala?
...ColumnB", "ColumnC")
val columns_original = original_array(0)
for (column_now <- columns_subset) {
sub_array += original_array.map{_(columns_original.indexOf(column_now))}
}
sub_array
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Flatten an Array of Arrays in Swift
Is there a counterpart in Swift to flatten in Scala, Xtend, Groovy, Ruby and co?
14 Answers
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Is it better to use Enumerable.Empty() as opposed to new List() to initialize an IEnumerable
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I think most postings missed the main point. Even if you use empty array or empty list, those are objects and they are stored in memory. Than Garbage Collector has to take care of them. If you are dealing with high throughput application, it could be noticeable impact.
Enum...
Rails: create on has_one association
...ser = current_user
@shop = Shop.create(params[:shop])
@user.shop = @shop
Now here's why your version did not work:
You probably thought that this might work because if User had a has_many relation to Shop, @user.shops.create(params[:shop]) would work. However there is a big difference between has...
What's the idiomatic syntax for prepending to a short python list?
...icient, because in Python, a list is an array of pointers, and Python must now take every pointer in the list and move it down by one to insert the pointer to your object in the first slot, so this is really only efficient for rather short lists, as you ask.
Here's a snippet from the CPython source...
Single Page Application: advantages and disadvantages [closed]
...ome reads when he/she opens his/her mail account. I read >50 at one go. now the structure of the mails is almost the same. if you will use a server side rendering scheme the server would then render it on every request(typical case).
- security concern - you should/ should not keep separate ...
Difference between del, remove and pop on lists
Is there any difference between the above three methods to remove an element from a list?
11 Answers
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When does a process get SIGABRT (signal 6)?
...alled
terminate called without an active exception
Aborted (core dumped)
now lets quickly see the core file, and validate that SIGABRT was indeed called:
gdb aa core
see regs:
i r
rdx 0x6 6
rsi 0x69a 1690
rdi 0x69a 1690
rip 0x7feae3170c37
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Setting JDK in Eclipse
...te to Computer > Windows C: > Program Files > Java, then click OK
Now you should see all installed JREs, select the one you want
Click OK/Finish a million times
Easy.... not.
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