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Is there any pythonic way to combine two dicts (adding values for keys that appear in both)?
...rom collections import Counter
>>> A = Counter({'a':1, 'b':2, 'c':3})
>>> B = Counter({'b':3, 'c':4, 'd':5})
>>> A + B
Counter({'c': 7, 'b': 5, 'd': 5, 'a': 1})
Counters are basically a subclass of dict, so you can still do everything else with them you'd normally do wit...
Elegant ways to support equivalence (“equality”) in Python classes
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342
Consider this simple problem:
class Number:
def __init__(self, number):
self.num...
How to make the 'cut' command treat same sequental delimiters as one?
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edited Apr 23 '18 at 23:03
Austin Adams
6,45533 gold badges2020 silver badges2727 bronze badges
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Most efficient way to prepend a value to an array
...-O but certainly using the unshift method is more concise:
var a = [1, 2, 3, 4];
a.unshift(0);
a; // => [0, 1, 2, 3, 4]
[Edit]
This jsPerf benchmark shows that unshift is decently faster in at least a couple of browsers, regardless of possibly different big-O performance if you are ok with mo...
kill -3 to get java thread dump
I am using kill -3 command to see the JVM's thread dump in unix. But where can I find the output of this kill command? I am lost!!
...
What is the difference between int, Int16, Int32 and Int64?
What is the difference between int , System.Int16 , System.Int32 and System.Int64 other than their sizes?
10 Answers
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Swift make method parameter mutable?
...
As stated in other answers, as of Swift 3 placing var before a variable has been deprecated. Though not stated in other answers is the ability to declare an inout parameter. Think: passing in a pointer.
func reduceToZero(_ x: inout Int) {
while (x != 0) {
...
Pandas selecting by label sometimes return Series, sometimes returns DataFrame
... other ways, but in my opinion this is the cleanest.
In [2]: type(df.loc[[3]])
Out[2]: pandas.core.frame.DataFrame
In [3]: type(df.loc[[1]])
Out[3]: pandas.core.frame.DataFrame
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No module named _sqlite3
...ect this problem with the steps below:
Install sqlite-devel (or libsqlite3-dev on some Debian-based systems)
Re-configure and re-compiled Python with ./configure --enable-loadable-sqlite-extensions && make && sudo make install
Note
The sudo make install part will set that pyth...
What is the difference between HashSet and List?
...and hashSet2
//returns a list of distinct items in both sets
HashSet set3 = set1.Union( set2 );
flies in comparison with an equivalent operation using LINQ. It's also neater to write!
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