np.where(pd.isnull(df)) returns the row and column indices where the value is NaN: In [152]: import numpy as np In [153]: import pandas as pd In [154]: np.where(pd.isnull(df)) Out[154]: (array([2, 5, 6, 6, 7, 7]), array([7, 7, 6, 7, 6, 7])) In [155]: df.iloc[2,7] Out[155]: nan In [160]: [df.iloc[i,j] for i,j in zip(*np.where(pd.isnull(df)))] Out[160]: [nan, nan, … Read more
You can simply convert the List using Scala’s JavaConverters: import scala.collection.JavaConverters._ def findAllQuestion():List[Question] = { questionDao.getAllQuestions().asScala.toList }
String is not a data type in Erlang, it’s just a list of integers. But Erlang shell try to display lists as strings if possible: 1> S = [65, 66, 67, 68, 69, 70]. “ABCDEF” 2> S = “ABCDEF”. “ABCDEF” 3> io:write(S). [65,66,67,68,69,70]ok 4> [65, 66]. “AB” 5> [65, 66, 1]. [65,66,1]
Here’s a continuation-based version. It’s tail-recursive and returns the list in the original order. let partitionWhileCps c l = let rec aux f = function | h::t when c h -> aux (fun (acc, l) -> f ((h::acc), l)) t | l -> f ([], l) aux id l Here are some benchmarks to go … Read more
I suspect there are more pythonic ways of doing it, but at least it gets the job done: l=list(‘abcdefgh’) pat=list(‘de’) print pat in l # Returns False print any(l[i:i+len(pat)]==pat for i in xrange(len(l)-len(pat)+1))
def pairs(lst): i = iter(lst) first = prev = item = i.next() for item in i: yield prev, item prev = item yield item, first Works on any non-empty sequence, no indexing required.
There is a shuffle method in the List class. The methods shuffles the list in place. You can call it without an argument or provide a random number generator instance: var list = [‘a’, ‘b’, ‘c’, ‘d’]; list.shuffle(); print(‘$list’); The collection package comes with a shuffle function/extension that also supports specifying a sub range to … Read more