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Create list of single item repeated N times
... mutable empty list, set, or dict, you should do something like this:
list_of_lists = [[] for _ in columns]
The underscore is simply a throwaway variable name in this context.
If you only have the number, that would be:
list_of_lists = [[] for _ in range(4)]
The _ is not really special, but y...
Usage of protocols as array types and function parameters in swift
...help overcome this limitation in some cases.
struct AnyX {
private let _x: () -> Int
var x: Int { return _x() }
init<T: X>(_ some: T) {
_x = { some.x }
}
}
// Usage Example
struct XY: X {
var x: Int
var y: Int
}
struct XZ: X {
var x: Int
var z: In...
How can I use getSystemService in a non-activity class (LocationManager)?
...
You can go for this :
getActivity().getSystemService(Context.CONNECTIVITY_SERVICE);
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python list in sql query as parameter
... cursor.execute(f'SELECT name FROM students WHERE id IN ({','.join('?' for _ in l)})', l). @bobince, you should also remark in your solution that using ? is the safe way to go in terms of avoid SQL injection. There are a lot of answers here that are vulnerable, basically any that concatenates string...
Numeric for loop in Django templates
...onal context. Sometimes this comes in handy
{% for i in '0123456789'|make_list %}
{{ forloop.counter }}
{% endfor %}
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Standard deviation of a list
...calculating the standard deviation of iterables like yours:
>>> A_rank = [0.8, 0.4, 1.2, 3.7, 2.6, 5.8]
>>> import statistics
>>> statistics.stdev(A_rank)
2.0634114147853952
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/bin/sh: pushd: not found
... If it's just a oneliner, the following may also work (cd /new_path ; command )
– barney765
Aug 5 '17 at 7:31
...
Changing selection in a select with the Chosen plugin
...-selected", function() {
var locID = jQuery(this).attr('class').split('__').pop();
// I have a class name: class="result-selected locvalue__209"
var arrayCurrent = jQuery('#searchlocation').val();
var index = arrayCurrent.indexOf(locID);
if (index > -1) {
arrayCurrent....
In CMake, how can I test if the compiler is Clang?
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A reliable check is to use the CMAKE_<LANG>_COMPILER_ID variables. E.g., to check the C++ compiler:
if (CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
# using Clang
elseif (CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
# using GCC
elseif (CMAKE_CXX_COMPILER_ID STREQ...
How can I escape square brackets in a LIKE clause?
...derscore from a query, so I ended up with this:
WHERE b.[name] not like '\_%' escape '\' -- use \ as the escape character
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