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Multiple aggregations of the same column using pandas GroupBy.agg()
...
# '0.25.0.dev0+840.g989f912ee'
# Setup
df = pd.DataFrame({'kind': ['cat', 'dog', 'cat', 'dog'],
'height': [9.1, 6.0, 9.5, 34.0],
'weight': [7.9, 7.5, 9.9, 198.0]
})
df.groupby('kind').agg(
max_height=('height', 'max...
How to count duplicate value in an array in javascript
...lke: The expression counts[x] || 0 returns the value of counts[x] if it is set, otherwise 0. Then just add one and set it again in the object and the count is done.
– Constantinius
Feb 7 '17 at 11:52
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Clone private git repo with dockerfile
... -y git
# Make ssh dir
RUN mkdir /root/.ssh/
# Copy over private key, and set permissions
# Warning! Anyone who gets their hands on this image will be able
# to retrieve this private key file from the corresponding image layer
ADD id_rsa /root/.ssh/id_rsa
# Create known_hosts
RUN touch /root/.ssh/...
How to normalize a NumPy array to within a certain range?
... default state. The argument copy performs the operation in-place if it is set to False. Documentation here.
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Hidden Features of SQL Server
... while deleted refers to the old values before the UPDATE:
UPDATE (table)
SET field1 = value1, field2 = value2
OUTPUT inserted.ID, deleted.field1, inserted.field1
WHERE (condition)
If a lot of info will be returned, the output of OUTPUT can also be redirected to a temporary table or a table varia...
Operator Overloading with C# Extension Methods
... StringBuilder = sb; }
public StringBuilder StringBuilder { get; private set; }
public static implicit operator StringBuilderWrapper(StringBuilder sb) {
return new StringBuilderWrapper(sb);
}
public static StringBuilderWrapper operator +(StringBuilderWrapper sbw, string s) {
sbw...
Is there a performance difference between i++ and ++i in C?
Is there a performance difference between i++ and ++i if the resulting value is not used?
14 Answers
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Is it possible to read the value of a annotation in java?
..., e.g.
Reflections reflections = new Reflections("my.project.prefix");
Set<Field> ids = reflections.getFieldsAnnotatedWith(javax.persistence.Id.class);
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C++使用OLE/COM高速读写EXCEL的源码 - C/C++ - 清泛网 - 专注C/C++及内核技术
...yunhe/archive/2011/09/25/2190485.html
http://blog.sina.com.cn/s/blog_6e51df7f01015cci.html
感谢原作者的无私奉献。
通过VC实现对Excel表格的操作的方法有多种，如：通过ODBC数据库实现，通过解析Excel表格文件，通过OLE/COM的实现。本文主要研究通...
Pickle or json?
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I have tried several methods and found out that using cPickle with setting the protocol argument of the dumps method as: cPickle.dumps(obj, protocol=cPickle.HIGHEST_PROTOCOL) is the fastest dump method.
import msgpack
import json
import pickle
import timeit
import cPickle
import numpy as np...