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How to filter Pandas dataframe using 'in' and 'not in' like in SQL
...to_keep)
0 False
1 True
2 False
3 True
Name: country, dtype: bool
>>> df[df.country.isin(countries_to_keep)]
country
1 UK
3 China
>>> df[~df.country.isin(countries_to_keep)]
country
0 US
2 Germany
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How expensive is RTTI?
I understand that there is a resource hit from using RTTI, but how big is it? Everywhere I've looked just says that "RTTI is expensive," but none of them actually give any benchmarks or quantitative data reguarding memory, processor time, or speed.
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What does the keyword Set actually do in VBA?
Hopefully an easy question, but I'd quite like a technical answer to this!
7 Answers
7...
Fastest way to check if a string matches a regexp in ruby?
... is the fastest way to check if a string matches a regular expression in Ruby?
7 Answers
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How to insert an item into an array at a specific index (JavaScript)?
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What you want is the splice function on the native array object.
arr.splice(index, 0, item); will insert item into arr at the specified index (deleting 0 items first, that is, it's just an insert).
In this example we will create an array and add an element to it into index 2:
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Make copy of an array
I have an array a which is constantly being updated. Let's say a = [1,2,3,4,5] . I need to make an exact duplicate copy of a and call it b . If a were to change to [6,7,8,9,10] , b should still be [1,2,3,4,5] . What is the best way to do this? I tried a for loop like:
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PHPUnit: assert two arrays are equal, but order of elements not important
What is a good way to assert that two arrays of objects are equal, when the order of the elements in the array is unimportant, or even subject to change?
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Why can't I initialize non-const static member or static array in class?
Why can't I initialize non-const static member or static array in a class?
5 Answers
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What is the optimal Jewish toenail cutting algorithm?
...simply put their feet in it and run it instead of having to manually do it by biting them or using nail clippers.
6 Answers...
Modular multiplicative inverse function in Python
...ule contain a function to compute modular multiplicative inverse of a number, i.e. a number y = invmod(x, p) such that x*y == 1 (mod p) ? Google doesn't seem to give any good hints on this.
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