comparison

问题 One of the practices I have gotten into in Python from the beginning is to reduce the number of variables I create as compared to the number I would create when trying to do the same thing in SAS or Fortran for example here is some code I wrote tonight: def idMissingFilings(dEFilings,indexFilings): inBoth=set(indexFilings.keys()).intersection(dEFilings.keys()) missingFromDE=[] for each in inBoth: if len(dEFilings[each])<len(indexFilings[each]): dEtemp=[] for filing in dEFilings[each]:

问题 One of the practices I have gotten into in Python from the beginning is to reduce the number of variables I create as compared to the number I would create when trying to do the same thing in SAS or Fortran for example here is some code I wrote tonight: def idMissingFilings(dEFilings,indexFilings): inBoth=set(indexFilings.keys()).intersection(dEFilings.keys()) missingFromDE=[] for each in inBoth: if len(dEFilings[each])<len(indexFilings[each]): dEtemp=[] for filing in dEFilings[each]:

问题 I have come across some Javascript code recently that looks like this: var foo = 'blah'; bar = function(){ // append some content to the body } doStuff = function(){ if(somethingIsTrue){ // do something } else { // do something else } foo && bar(); } doStuff(); The foo && bar() expression logs to the console as 'undefined'. I get why it might call the bar function to run from inside the doStuff function but why is it used as a comparison expression with the foo variable? 回答1: It means call

问题 I have 2 android intent objects that can be persisted as URLs and then rehydrated back into intent objects. I'm wondering what is the most effective way to compare any 2 intent objects to ensure that they end up resolving to the same activity with the same parameters etc. Using intent.filterEquals does this, but it does not include the extras. Currently my code for the equals method looks like this: Intent a = Intent.parseUri(this.intentUrl, Intent.URI_INTENT_SCHEME); Intent b = Intent

问题 Looking for a more efficient way to loop over and compare datetimeindex values in two Series objects with different frequencies. Setup Imagine two Pandas series, each with a datetime index covering the same year span yet with different frequencies for each index. One has a frequency of days, the other a frequency of hours. range1 = pd.date_range('2016-01-01','2016-12-31', freq='D') range2 = pd.date_range('2016-01-01','2016-12-31', freq='H') I'm trying to loop over these series using their

问题 I am creating an S3 class in R for which I would like to be able to do comparisons like "<" , ">" , and "==" . Rather than implement each of these separately from what I've read about group generics I believe I can do so using Ops() but I haven't found any good examples of how to do this. Suffice it to say that for myClass I can create an as.integer.myClass() function, and that to compare a and b I could just convert to integer first: if(as.integer(a) < as.integer(b)) foo This totally works,

问题 Scala does not provide chained comparisons as Python does: // Python: 0 < x <= 3 // Scala: 0 < x && x <= 3 Will Scala 2.10 with the new macro feature enable the programmer write a library that adds this feature? Or is this beyond the scope of Scala's macros? Macros seem to be the right choice for the implementation of such syntactic sugar as they do not complicate the parser/compiler. 回答1: You don't need macros for it: class ChainedComparisons[T : Ordering](val res: Boolean, right: T) { def <

问题 I have two python lists, A = [ 1, 2, 3, 4, 5 ] B = [ True, False, False, True, True ] lists A and B are the same length. I want to sum only the elements in A that correspond to True elements in B. I know I can do that with something like: sum([A[x] for x in xrange(len(A)) if B[x]]) but I was wondering if there was a more elegant solution that didn't involve looping over elements in each list? 回答1: Using itertools.compress: >>> from itertools import compress >>> sum(compress(A, B)) 10 The

问题 I am trying to determine that standard SQL behaviour for comparing a number to a character or string version of the same number. Does SELECT 1 = '1' (or the like) always return some sort of "truthy" value ( true , 1 , 't' , etc.)? I have confirmed as much on PostgreSQL and MySQL, but I cannot find a resource for SQL as a whole. Update: The purpose for the question is that I'm trying to figure out if using a number, without the quotes, will work when selecting/inserting/updating/etc. from a

问题 How do I compare two Doctrine_Record objects to see if they are "equal"? On the domain login I am considering, two objects are equal if they have the same properties values, except the id and the created_at and updated_at fields (a la Timestampable ). 回答1: First idea which comes into my mind is: class User extends Doctrine_Record { public function equals(User $user) { $left = $this->toArray(); $right = $user->toArray(); unset($left['id'], $left['created_at'], $left['updated_at']); unset(