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How do I get the row count of a pandas DataFrame?
I'm trying to get the number of rows of dataframe df with Pandas, and here is my code.
14 Answers
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Select values from XML field in SQL Server 2008
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You must use .nodes() and cross apply if xmlField contains more than one <person> elements.
– Remus Rusanu
May 22 '09 at 18:45
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What's the difference between @JoinColumn and mappedBy when using a JPA @OneToMany association
...indicates that the entity in this side is the inverse of the relationship, and the owner resides in the "other" entity. This also means that you can access the other table from the class which you've annotated with "mappedBy" (fully bidirectional relationship).
In particular, for the code in the qu...
Google Maps Android API v2 - Interactive InfoWindow (like in original android google maps)
...dow. It's quite easy - one only has to listen to the OnMarkerClickListener and then show a custom PopupWindow above the marker. Some other guys here on StackOverflow suggested this solution and it actually looks quite good at first glance. But the problem with this solution shows up when you start t...
Is the 'override' keyword just a check for a overridden virtual method?
As far as I understand, the introduction of override keyword in C++11 is nothing more than a check to make sure that the function being implemented is the override ing of a virtual function in the base class.
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How do you check in python whether a string contains only numbers?
...u'll want to use the isdigit method on your str object:
if len(isbn) == 10 and isbn.isdigit():
From the isdigit documentation:
str.isdigit()
Return True if all characters in the string are digits and there is at least one character, False otherwise. Digits include decimal characters and digits tha...
Executors.newCachedThreadPool() versus Executors.newFixedThreadPool()
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I think the docs explain the difference and usage of these two functions pretty well:
newFixedThreadPool
Creates a thread pool that reuses a
fixed number of threads operating off
a shared unbounded queue. At any
point, at most nThreads threads will
be...
how to listen to N channels? (dynamic select statement)
...cks until at least one of the cases can
proceed, makes a uniform pseudo-random choice, and then executes that
case. It returns the index of the chosen case and, if that case was a
receive operation, the value received and a boolean indicating whether
the value corresponds to a send on the ch...
C state-machine design [closed]
I am crafting a small project in mixed C and C++. I am building one small-ish state-machine at the heart of one of my worker thread.
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When vectors are allocated, do they use memory on the heap or the stack?
... store.
vector<Type*> vect;
will allocate the vector on the stack and a bunch of pointers on the free store, but where these point is determined by how you use them (you could point element 0 to the free store and element 1 to the stack, say).
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