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What is the difference between NaN and None?
...= pd.Series([1, None], dtype=object)
s_good = pd.Series([1, np.nan])
In [13]: s_bad.dtype
Out[13]: dtype('O')
In [14]: s_good.dtype
Out[14]: dtype('float64')
Jeff comments (below) on this:
np.nan allows for vectorized operations; its a float value, while None, by definition, forces object ty...
Why should I prefer single 'await Task.WhenAll' over multiple awaits?
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edited Jun 25 '19 at 16:31
answered Aug 19 '13 at 10:02
u...
How can I safely create a nested directory?
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On Python ≥ 3.5, use pathlib.Path.mkdir:
from pathlib import Path
Path("/my/directory").mkdir(parents=True, exist_ok=True)
For older versions of Python, I see two answers with good qualities, each with a small flaw, so I will give my ...
How are multi-dimensional arrays formatted in memory?
...eter, bad things are going to happen. Here's a quick example:
int array1[3][2] = {{0, 1}, {2, 3}, {4, 5}};
In memory looks like this:
0 1 2 3 4 5
exactly the same as:
int array2[6] = { 0, 1, 2, 3, 4, 5 };
But if you try to pass array1 to this function:
void function1(int **a);
you'll ge...
Extract file name from path, no matter what the os/path format
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edited Apr 28 '13 at 21:12
answered Dec 5 '11 at 11:45
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Can I restore deleted files (undo a `git clean -fdx`)?
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132
No. Those files are gone.
(Just checked on Linux: git clean calls unlink(), and does not backu...
Escaping single quote in PHP when inserting into MySQL [duplicate]
...hese strings (in both snippets) with mysql_real_escape_string().
http://us3.php.net/mysql-real-escape-string
The reason your two queries are behaving differently is likely because you have magic_quotes_gpc turned on (which you should know is a bad idea). This means that strings gathered from $_GE...
shortcut in Android Studio to locate the current editing src file
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edited Jan 23 '19 at 4:49
answered Sep 7 '15 at 10:32
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How can I open Windows Explorer to a certain directory from within a WPF app?
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314
Why not Process.Start(@"c:\test");?
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Cannot serve WCF services in IIS on Windows 8
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Callum Watkins
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answered Jul 12 '12 at 20:35
faesterfaester
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