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Find integer index of rows with NaN in pandas dataframe
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For DataFrame df:
import numpy as np
index = df['b'].index[df['b'].apply(np.isnan)]
will give you back the MultiIndex that you can use to index back into df, e.g.:
df['a'].ix[index[0]]
>>> 1.452354
For the integer index:
df_index = df.index.values.tolist()
[d...
Is there a way to provide named parameters in a function call in JavaScript?
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ES2015 and later
In ES2015, parameter destructuring can be used to simulate named parameters. It would require the caller to pass an object, but you can avoid all of the checks inside the function if you also use default parameters:
myFunction({ param1 : 70, param2 : 175});
func...
Cosine Similarity between 2 Number Lists
I need to calculate the cosine similarity between two lists , let's say for example list 1 which is dataSetI and list 2 which is dataSetII . I cannot use anything such as numpy or a statistics module. I must use common modules (math, etc) (and the least modules as possible, at that, to reduc...
Where is the C auto keyword used?
In my college days I read about the auto keyword and in the course of time I actually forgot what it is. It is defined as:
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comparing 2 strings alphabetically for sorting purposes
I'm trying to compare 2 strings alphabetically for sorting purposes. For example I want to have a boolean check like if('aaaa' < 'ab') . I tried it, but it's not giving me correct results, so I guess that's not the right syntax. How do I do this in jquery or Javascript?
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How to merge two arrays in JavaScript and de-duplicate items
...gh", "Shakya"];
const array3 = [...array1, ...array2];
Since there is no 'built in' way to remove duplicates (ECMA-262 actually has Array.forEach which would be great for this), we have to do it manually:
Array.prototype.unique = function() {
var a = this.concat();
for(var i=0; i<a.lengt...
Usage of __slots__?
...ts__ and what are the cases one should avoid this?
TLDR:
The special attribute __slots__ allows you to explicitly state which instance attributes you expect your object instances to have, with the expected results:
faster attribute access.
space savings in memory.
The space savings is from
Stori...
Inline functions vs Preprocessor macros
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Preprocessor macros are just substitution patterns applied to your code. They can be used almost anywhere in your code because they are replaced with their expansions before any compilation starts.
Inline functions are actual functions whose body is direc...
Combining two Series into a DataFrame in pandas
... Series s1 and s2 with the same (non-consecutive) indices. How do I combine s1 and s2 to being two columns in a DataFrame and keep one of the indices as a third column?
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Logical operators (“and”, “or”) in DOS batch
How would you implement logical operators in DOS Batch files?
12 Answers
12
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