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How do I add the contents of an iterable to a set?
What is the "one [...] obvious way" to add all items of an iterable to an existing set ?
6 Answers
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Postgres - FATAL: database files are incompatible with server
...an run the below command to upgrade your postgres data directory retaining all data:
brew postgresql-upgrade-database
The above command is taken from the output of brew info postgres
share
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impr...
Dealing with commas in a CSV file
...any easily-available csv library - that is to say RFC 4180.
There's actually a spec for CSV format and how to handle commas:
Fields containing line breaks (CRLF), double quotes, and commas should be enclosed in double-quotes.
http://tools.ietf.org/html/rfc4180
So, to have values foo and ...
Reverse a string in Python
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@Tanner [::-1] is fastest because it does not call any external functions, rather it's using slicing, which is highly-optimized in python. ''.join(list(reversed(s))) makes 3 function calls.
– hd1
Apr 27 at 13:51
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TypeScript sorting an array
..., b) {
var ax = [], bx = [];
a.replace(/(\d+)|(\D+)/g, function (_, $1, $2) { ax.push([$1 || Infinity, $2 || ""]) });
b.replace(/(\d+)|(\D+)/g, function (_, $1, $2) { bx.push([$1 || Infinity, $2 || ""]) });
while (ax.length && bx.length) {
var an = ax.shift();
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Python Pandas merge only certain columns
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You can use .loc to select the specific columns with all rows and then pull that. An example is below:
pandas.merge(dataframe1, dataframe2.iloc[:, [0:5]], how='left', on='key')
In this example, you are merging dataframe1 and dataframe2. You have chosen to do an outer left jo...
Mimicking sets in JavaScript?
...the list is a little safer with this:
if (Object.prototype.hasOwnProperty.call(obj, A))
// put code here
}
because of potential conflict between built-in methods and/or properties on the base Object like the constructor property.
Sidebar on ES6: The current working version of ECMAScript 6 or s...
How to call base.base.method()?
...Derived
{
public override void Say()
{
Console.WriteLine("Called from Special Derived.");
var ptr = typeof(Base).GetMethod("Say").MethodHandle.GetFunctionPointer();
var baseSay = (Action)Activator.CreateInstance(typeof(Action), this, ptr);
baseSay(...
Python strftime - date without leading 0?
...omment until now. It turns out that datetime specifies a very interesting __format__ hook that allows you to write things like that.
– mgilson
Dec 4 '14 at 0:26
2
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Why does modern Perl avoid UTF-8 by default?
...?????????????????????
Set your PERL_UNICODE envariable to AS. This makes all Perl scripts decode @ARGV as UTF‑8 strings, and sets the encoding of all three of stdin, stdout, and stderr to UTF‑8. Both these are global effects, not lexical ones.
At the top of your source file (program, module, l...