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How do I dump an object's fields to the console?
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Adding an inspect method to your class allows you to define how the class' attributes are displayed, rather than rely on default output. A lot of classes don't implement it well, but it can be really useful when debugging. Ruby will fall back to to_s if it can't f...
while (1) vs. while(True) — Why is there a difference (in python 2 bytecode)?
...me byte code for while(True): pass and while(1): pass , but this is actually not the case in python2.7.
3 Answers
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mongodb group values by multiple fields
... $slice just off the basic aggregation result. For "large" results, run parallel queries instead for each grouping ( a demonstration listing is at the end of the answer ), or wait for SERVER-9377 to resolve, which would allow a "limit" to the number of items to $push to an array.
db.books.aggregate(...
Regex lookahead, lookbehind and atomic groups
...ely follow, and stop as backtracking is disabled
A non-atomic group will allow backtracking; if subsequent matching ahead fails, it will backtrack and use alternative patterns until a match for the entire expression is found or all possibilities are exhausted.
(foo|foot)s applied to foots will:
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Where to get “UTF-8” string literal in Java?
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You don't really need to call name() at all. You can directly pass the Charset object into the InputStreamReader constructor.
– Natix
Nov 19 '14 at 10:33
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Cannot kill Python script with Ctrl-C
...you can't do anything with it after it exits. The process will finish when all non-daemon threads have finished; parent-child relationships don't come into that.
– Thomas K
Dec 6 '13 at 22:22
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How to pick just one item from a generator?
... would use the second syntax given in my answer, next(g). This will internally call g.__next__(), but you don't really have to worry about that, just as you usually don't care that len(a) internally calls a.__len__().
– Sven Marnach
Apr 10 '14 at 10:31
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How can I have a newline in a string in sh?
...rom the Bash manual page:
Words of the form $'string' are treated specially. The word expands to
string, with backslash-escaped characters replaced as specified by the
ANSI C standard. Backslash escape sequences, if present, are decoded
as follows:
\a alert (bell)
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How to properly reuse connection to Mongodb across NodeJs application and modules
...lhost:27017";
var _db;
module.exports = {
connectToServer: function( callback ) {
MongoClient.connect( url, { useNewUrlParser: true }, function( err, client ) {
_db = client.db('test_db');
return callback( err );
} );
},
getDb: function() {
return _db;
}
};
To...
Catch an exception thrown by an async void method
...ET,
is it possible to catch an exception thrown by an async method in the calling method?
6 Answers
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