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C++ inheritance - inaccessible base?
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The default inheritance type of a class in C++ is private, so any public and protected members from the base class are limited to private. struct inheritance on the other hand is public by default.
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How to get the first column of a pandas DataFrame as a Series?
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>>> import pandas as pd
>>> df = pd.DataFrame({'x' : [1, 2, 3, 4], 'y' : [4, 5, 6, 7]})
>>> df
x y
0 1 4
1 2 5
2 3 6
3 4 7
>>> s = df.ix[:,0]
>>> type(s)
<class 'pandas.core.series.Serie...
Filtering collections in C#
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If you're using C# 3.0 you can use linq, way better and way more elegant:
List<int> myList = GetListOfIntsFromSomewhere();
// This will filter out the list of ints that are > than 7, Where returns an
// IEnumerable<T> so a call to ToList is required to convert...
NameError: name 'self' is not defined
...ot refer each other.
It's a common pattern to default an argument to None and add a test for that in code:
def p(self, b=None):
if b is None:
b = self.a
print b
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How to create duplicate allowed attributes
... AttributeUsage attribute onto your Attribute class (yep, that's mouthful) and set AllowMultiple to true:
[AttributeUsage(AttributeTargets.Method, AllowMultiple = true)]
public sealed class MyCustomAttribute: Attribute
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串口通信器使用指导 · App Inventor 2 中文网
...发、半包处理和校验；不会控制继电器或擅自配置设备。Android 手机需要支持 USB 主机/OTG，连接驱动支持的 USB 转串口模块。将模块自己的 TX 与 RX 接在一起形成回显，再连接手机；已有设备固件实现原样回显时可直接用该设备。...
Is there auto type inferring in Java?
...whose scope is within the block where they have been defined. Similar to C and C++, but there is no auto or register keyword. However, the Java compiler will not allow the usage of a not-explicitly-initialized local variable and will give a compilation error (unlike C and C++ where the compiler will...
MySql - Way to update portion of a string?
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Use the LIKE operator to find the rows that you care about and update them using the REPLACE function.
For example:
UPDATE table_name SET field_name = REPLACE(field_name,'search','replace') WHERE field_name LIKE '%some_value%'
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How to check if multiple array keys exists
...x the only issue is that if $keys contains one element that is not in $arr and another that is in it, !array_diff_key returns empty => false (3v4l example)...
– CPHPython
Aug 17 '18 at 10:10
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Calling a class function inside of __init__
I'm writing some code that takes a filename, opens the file, and parses out some data. I'd like to do this in a class. The following code works:
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