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How to know/change current directory in Python shell?
...now how to change.
edit
Under Windows:
set PYTHONPATH=%PYTHONPATH%;C:\My_python_lib
(taken from http://docs.python.org/using/windows.html)
edit 2
... and even better: use virtualenv and virtualenv_wrapper, this will allow you to create a development environment where you can add module paths ...
Analyze audio using Fast Fourier Transform
...efficients you get out will be imaginary numbers even though your input is all real values. In order to get the amount of power in each frequency, you need to calculate the magnitude of the FFT coefficient for each frequency. This is not just the real component of the coefficient, you need to calcul...
Iterate over a list of files with spaces
...
Seems like pointing out the obvious, but in nearly all simple cases, -exec is going to be cleaner than an explicit loop: find . -iname "foo*" -exec echo "File found: {}" \;. Plus, in many cases you can replace that last \; with+ to put lots of files in the one command.
...
How can I remove the string “\n” from within a Ruby string?
... your gsub. The different quote marks behave differently.
Double quotes " allow character expansion and expression interpolation ie. they let you use escaped control chars like \n to represent their true value, in this case, newline, and allow the use of #{expression} so you can weave variables and...
How do you use the ? : (conditional) operator in JavaScript?
...
This is a one-line shorthand for an if-else statement. It's called the conditional operator.1
Here is an example of code that could be shortened with the conditional operator:
var userType;
if (userIsYoungerThan18) {
userType = "Minor";
} else {
userType = "Adult";
}
if (userIsY...
How do you do natural logs (e.g. “ln()”) with numpy in Python?
...
Correct, np.log(x) is the Natural Log (base e log) of x.
For other bases, remember this law of logs: log-b(x) = log-k(x) / log-k(b) where log-b is the log in some arbitrary base b, and log-k is the log in base k, e.g.
here k = e
l = np.l...
linux下iptables配置详解 - 更多技术 - 清泛网 - 专注C/C++及内核技术
... prot opt source destination
Chain RH-Firewall-1-INPUT (0 references)
target prot opt source destination
ACCEPT all -- 0.0.0.0/0 0.0.0.0/0
ACCEPT icmp -- 0.0.0.0/0 0.0.0.0/0 ...
Can I create a One-Time-Use Function in a Script or Stored Procedure?
...nderstand the security implications before you consider this.
DECLARE @add_a_b_func nvarchar(4000) = N'SELECT @c = @a + @b;';
DECLARE @add_a_b_parm nvarchar(500) = N'@a int, @b int, @c int OUTPUT';
DECLARE @result int;
EXEC sp_executesql @add_a_b_func, @add_a_b_parm, 2, 3, @c = @result OUTPUT;
PRI...
Check if SQL Connection is Open or Closed
... as an enum and not turn it into a string.....
– marc_s
Aug 4 '11 at 15:19
4
Should've added usin...
SQL Joins Vs SQL Subqueries (Performance)?
...explicit JOIN. In my experience IN is a very slow operator, since SQL normally evaluates it as a series of WHERE clauses separated by "OR" (WHERE x=Y OR x=Z OR...).
As with ALL THINGS SQL though, your mileage may vary. The speed will depend a lot on indexes (do you have indexes on both ID column...