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Pandas dataframe get first row of each group
...;> df.groupby('id').first()
value
id
1 first
2 first
3 first
4 second
5 first
6 first
7 fourth
If you need id as column:
>>> df.groupby('id').first().reset_index()
id value
0 1 first
1 2 first
2 3 first
3 4 second
4 5 first
5 6...
Integrate ZXing in Android Studio
...
234
I was integrating ZXING into an Android application and there were no good sources for the inpu...
Can't install Ruby under Lion with RVM – GCC issues
...
553
This answer was edited multiple times and now contains several alternative solutions. Try the...
Python - abs vs fabs
...(-2))
Out[7]: int
In [8]: type(abs(-2.0))
Out[8]: float
In [9]: type(abs(3+4j))
Out[9]: float
In [10]: type(math.fabs(-2))
Out[10]: float
In [11]: type(math.fabs(-2.0))
Out[11]: float
In [12]: type(math.fabs(3+4j))
---------------------------------------------------------------------------
Type...
Remove empty elements from an array in Javascript
... to remove null or undefined values:
var array = [0, 1, null, 2, "", 3, undefined, 3,,,,,, 4,, 4,, 5,, 6,,,,];
var filtered = array.filter(function (el) {
return el != null;
});
console.log(filtered);
It will depend on what you consider to be "empty" for example, if you were d...
Accessing last x characters of a string in Bash
I found out that with ${string:0:3} one can access the first 3 characters of a string. Is there a equivalently easy method to access the last three characters?
...
How can I obtain the element-wise logical NOT of a pandas Series?
... True, False, True])
In [8]: ~s
Out[8]:
0 False
1 False
2 True
3 False
dtype: bool
Using Python2.7, NumPy 1.8.0, Pandas 0.13.1:
In [119]: s = pd.Series([True, True, False, True]*10000)
In [10]: %timeit np.invert(s)
10000 loops, best of 3: 91.8 µs per loop
In [11]: %timeit ~s
10...
What are the correct version numbers for C#?
...numbers for C#? What came out when? Why can't I find any answers about C# 3.5 ?
12 Answers
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WinDBG用法详解 PDF - 文档下载 - 清泛网 - 专注C/C++及内核技术
...DBG具有非常大的灵活性和可扩展性，用来满足各种
第30章WinDBG用法详解...................................................................................................1
30.1工作空间......................................................................................
How do I get indices of N maximum values in a NumPy array?
...
365
The simplest I've been able to come up with is:
In [1]: import numpy as np
In [2]: arr = np....