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MySQL - Rows to Columns
...temvalue |
+--------+----------+-----------+
| 1 | A | 10 |
| 1 | B | 3 |
| 2 | A | 9 |
| 2 | C | 40 |
+--------+----------+-----------+
This will be our goal, the pretty pivot table:
select * from history_itemvalue_piv...
How to access pandas groupby dataframe by key
...group method:
In [21]: gb.get_group('foo')
Out[21]:
A B C
0 foo 1.624345 5
2 foo -0.528172 11
4 foo 0.865408 14
Note: This doesn't require creating an intermediary dictionary / copy of every subdataframe for every group, so will be much more memory-efficient that creating...
Shuffle two list at once with same order
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– Jaroslav Klimčík
Apr 25 '14 at 10:15
4
(noob question) - what does the * mean?
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Join a list of strings in python and wrap each string in quotation marks
...ords = ['hello', 'world', 'you', 'look', 'nice']
>>> ', '.join('"{0}"'.format(w) for w in words)
'"hello", "world", "you", "look", "nice"'
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Regex how to match an optional character
...e letter optional. {1} is redundant. (Of course you could also write [A-Z]{0,1} which would mean the same, but that's what the ? is there for.)
You could improve your regex to
^([0-9]{5})+\s+([A-Z]?)\s+([A-Z])([0-9]{3})([0-9]{3})([A-Z]{3})([A-Z]{3})\s+([A-Z])[0-9]{3}([0-9]{4})([0-9]{2})([0-9]{2})
...
What's quicker and better to determine if an array key exists in PHP?
...
10 Answers
10
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Generate random string/characters in JavaScript
...aracter string composed of characters picked randomly from the set [a-zA-Z0-9] .
77 Answers
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Attempt by security transparent method 'WebMatrix.WebData.PreApplicationStartCode.Start()'
...22587521/482256
– Kevin Nelson
Jun 10 '16 at 21:37
this fxed it for me but I also needed the below in assembly binding...
top命令使用详解 - 更多技术 - 清泛网 - 专注C/C++及内核技术
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