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How can I obtain the element-wise logical NOT of a pandas Series?
...: s = pd.Series([True, 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
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How to pass a single object[] to a params object[]
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100
A simple typecast will ensure the compiler knows what you mean in this case.
Foo((object)new ...
One-line list comprehension: if-else variants
...ssion you're returning for each element. Thus you need:
[ x if x%2 else x*100 for x in range(1, 10) ]
The confusion arises from the fact you're using a filter in the first example, but not in the second. In the second example you're only mapping each value to another, using a ternary-operator exp...
Split list into multiple lists with fixed number of elements
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214
I think you're looking for grouped. It returns an iterator, but you can convert the result to a...
Combining two lists and removing duplicates, without removing duplicates in original list
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11 Answers
11
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How do I use the includes method in lodash to check if an object is in the collection?
...s will work because there is only one instance of {"b": 2}:
var a = {"a": 1}, b = {"b": 2};
_.includes([a, b], b);
> true
On the other hand, the where(deprecated in v4) and find methods compare objects by their properties, so they don't require reference equality. As an alternative to includes...
How can I check if multiplying two numbers in Java will cause an overflow?
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14 Answers
14
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What does value & 0xff do in Java?
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173
It sets result to the (unsigned) value resulting from putting the 8 bits of value in the lowes...
Getting and removing the first character of a string
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170
See ?substring.
x <- 'hello stackoverflow'
substring(x, 1, 1)
## [1] "h"
substring(x, 2)
#...
What's the difference between --general-numeric-sort and --numeric-sort options in gnu sort
...ic sort compares the numbers as floats, this allows scientific notation eg 1.234E10 but is slower and subject to rounding error (1.2345678 could come after 1.2345679), numeric sort is just a regular alphabetic sort that knows 10 comes after 9.
See http://www.gnu.org/software/coreutils/manual/h...