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Does pandas iterrows have performance issues?
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Generally, iterrows should only be used in very, very specific cases. This is the general order of precedence for performance of various operations:
1) vectorization
2) using a custom cython routine
3) apply
a) reductions that can be performed in cytho...
JPA CascadeType.ALL does not delete orphans
I am having trouble deleting orphan nodes using JPA with the following mapping
11 Answers
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Show diff between commits
I am using Git on Ubuntu 10.04 (Lucid Lynx).
11 Answers
11
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Python-equivalent of short-form “if” in C++ [duplicate]
Is there a way to write this C/C++ code in Python?
a = (b == true ? "123" : "456" )
4 Answers
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Use a list of values to select rows from a pandas dataframe [duplicate]
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You can use isin method:
In [1]: df = pd.DataFrame({'A': [5,6,3,4], 'B': [1,2,3,5]})
In [2]: df
Out[2]:
A B
0 5 1
1 6 2
2 3 3
3 4 5
In [3]: df[df['A'].isin([3, 6])]
Out[3]:
A B
1 6 2
2 3 3
And to get the opposite use ~:
In [4]: df[~df['A'].isin([3, 6])]
Out[4]:
A B...
error: cannot dynamic_cast ‘b’ (of type ‘class Base*’) to type ‘c...
error: cannot dynamic_cast ‘b’ (of type ‘class Base*’) to type ‘class Derived*’ (source type is not polymorphic)在将父类型转换为子类型时,可以使用static_cast和dynamic_cast.如果使用dynamic_cast,它要求父类必须为多态的,即要求至少有一个虚函数,因此....
Debian/Linux下安装OpenJDK8 - 操作系统(内核) - 清泛网 - 专注C/C++及内核技术
Debian/Linux下安装OpenJDK8linux_install_openjdk8因为Debian11的源里不再带OpenJDK8了，需要手工来安装。下载安装包因为手工安装，所以部分依赖包需要自己下载。wget http: snapshot debian org archive debian-security 202202 因为Debian11的源里不再带Open...
What key shortcuts are to comment and uncomment code?
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Keyboard accelerators are configurable. You can find out which keyboard accelerators are bound to a command in Tools -> Options on the Environment -> Keyboard page.
These commands are named Edit.CommentSelection and Edit.UncommentSelection.
(Wit...
Is there a function in python to split a word into a list? [duplicate]
Is there a function in python to split a word into a list of single letters? e.g:
7 Answers
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how do i remove a comma off the end of a string?
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Manse
36.1k88 gold badges7373 silver badges103103 bronze badges
answered Oct 29 '09 at 10:18
SigurdSigurd
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