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What's the Hi/Lo algorithm?
...dea is that you have two numbers to make up a primary key- a "high" number and a "low" number. A client can basically increment the "high" sequence, knowing that it can then safely generate keys from the entire range of the previous "high" value with the variety of "low" values.
For instance, suppo...
What is the difference between .*? and .* regular expressions?
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It is the difference between greedy and non-greedy quantifiers.
Consider the input 101000000000100.
Using 1.*1, * is greedy - it will match all the way to the end, and then backtrack until it can match 1, leaving you with 1010000000001.
.*? is non-greedy. * w...
TypeError: got multiple values for argument
I read the other threads that had to do with this error and it seems that my problem has an interesting distinct difference than all the posts I read so far, namely, all the other posts so far have the error in regards to either a user created class or a builtin system resource. I am experiencing th...
What does the “map” method do in Ruby?
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The map method takes an enumerable object and a block, and runs the block for each element, outputting each returned value from the block (the original object is unchanged unless you use map!):
[1, 2, 3].map { |n| n * n } #=> [1, 4, 9]
Array and Range are enume...
what is the difference between ?:, ?! and ?= in regex?
I searched for the meaning of these expressions but couldn't understand the exact difference between them.
This is what they say:
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pandas: multiple conditions while indexing data frame - unexpected behavior
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As you can see, the AND operator drops every row in which at least one
value equals -1. On the other hand, the OR operator requires both
values to be equal to -1 to drop them.
That's right. Remember that you're writing the condition in te...
Get first and last day of month using threeten, LocalDate
I have a LocalDate which needs to get the first and last day of the month.
How do I do that?
10 Answers
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What is the intent of the methods getItem and getItemId in the Android class BaseAdapter?
I'm curious about the purpose of the methods getItem and getItemId in the class Adapter in the Android SDK.
6 Answers
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How do I clone a Django model instance object and save it to the database?
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Just change the primary key of your object and run save().
obj = Foo.objects.get(pk=<some_existing_pk>)
obj.pk = None
obj.save()
If you want auto-generated key, set the new key to None.
More on UPDATE/INSERT here.
Official docs on copying model instances: h...
Which parts of Real World Haskell are now obsolete or considered bad practice?
...rsion 3.0.x.x. 6.10.1 already used 4.0.0.0, which introduced many changes. And that's just the jump from 6.8 to 6.10. The current version of GHC is 7.10. Monads have been changed. There's currently a discussion to remove return from Monad, so the Monad instance in Real World Haskell will really be o...