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How can I obtain the element-wise logical NOT of a pandas Series?
...~s:
In [7]: 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...
Specifying rails version to use when creating a new application
I have two versions of rails (2.1.0 and 2.2.2) installed in my computer.
7 Answers
7
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Resolve Type from Class Name in a Different Assembly
...assembly name like such:
Type.GetType("System.String, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089");
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Shell equality operators (=, ==, -eq)
... guaranteed to work.
$ a=foo
$ [ "$a" = foo ]; echo "$?" # POSIX sh
0
$ [ "$a" == foo ]; echo "$?" # bash specific
0
$ [ "$a" -eq foo ]; echo "$?" # wrong
-bash: [: foo: integer expression expected
2
(Side note: Quote those variable expansions! Do not leave out the double quotes ab...
Seeding the random number generator in Javascript
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edited May 23 '17 at 12:02
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answered Feb 6 '09 at 17:42
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What is the difference between exit(0) and exit(1) in C?
Can anyone tell me? What is the difference between exit(0) and exit(1) in C language?
11 Answers
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What does (x ^ 0x1) != 0 mean?
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The XOR operation (x ^ 0x1) inverts bit 0. So the expression effectively means: if bit 0 of x is 0, or any other bit of x is 1, then the expression is true.
Conversely the expression is false if x == 1.
So the test is the same as:
if (x != 1)
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how to convert array values from string to int?
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edited Apr 23 '19 at 10:46
Rahul
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How can I do DNS lookups in Python, including referring to /etc/hosts?
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Justin M. Keyes
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answered May 10 '10 at 18:36
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How do I find out if first character of a string is a number?
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260
Character.isDigit(string.charAt(0))
Note that this will allow any Unicode digit, not just 0-9....