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Replacement for “rename” in dplyr
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dplyr version 0.3 added a new rename() function that works just like plyr::rename().
df <- rename(df, new_name = old_name)
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imp...
jQuery select by attribute using AND and OR operators
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AND operation
a=$('[myc="blue"][myid="1"][myid="3"]');
OR operation, use commas
a=$('[myc="blue"],[myid="1"],[myid="3"]');
As @Vega commented:
a=$('[myc="blue"][myid="1"],[myc="blue"][myid="3"]');
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How to make lists contain only distinct element in Python? [duplicate]
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Mark ByersMark Byers
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How to create the most compact mapping n → isprime(n) up to a limit N?
...number with one bit e.g. for the given range of numbers (1, 10], starts at 3: 1110
31 Answers
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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...
Why do enum permissions often have 0, 1, 2, 4 values?
...are people always using enum values like 0, 1, 2, 4, 8 and not 0, 1, 2, 3, 4 ?
7 Answers
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Get operating system info
...t 10/i' => 'Windows 10',
'/windows nt 6.3/i' => 'Windows 8.1',
'/windows nt 6.2/i' => 'Windows 8',
'/windows nt 6.1/i' => 'Windows 7',
'/windows nt 6.0/i' =>...
Swapping column values in MySQL
...t. This method doesn't swap the values if one of them is NULL. Use method #3 that doesn't have this limitation.
UPDATE swap_test SET x=y, y=@temp WHERE (@temp:=x) IS NOT NULL;
This method was offered by Dipin in, yet again, the comments of http://beerpla.net/2009/02/17/swapping-column-values-in-mys...
How to concatenate properties from multiple JavaScript objects
...ation on Object.assign()
var o1 = { a: 1 };
var o2 = { b: 2 };
var o3 = { c: 3 };
var obj = Object.assign({}, o1, o2, o3);
console.log(obj); // { a: 1, b: 2, c: 3 }
Object.assign is supported in many modern browsers but not yet all of them. Use a transpiler like Babel and Traceur t...
What does the “yield” keyword do?
...ng its items one by one is called iteration:
>>> mylist = [1, 2, 3]
>>> for i in mylist:
... print(i)
1
2
3
mylist is an iterable. When you use a list comprehension, you create a list, and so an iterable:
>>> mylist = [x*x for x in range(3)]
>>> for i in my...