eval


Generating evalable python code: all combinations of functions in disjunctive normal form

|▌冷眼眸甩不掉的悲伤 提交于 2020-01-24 09:39:25
问题 (A,B,C) = (100, 200, 300) def f1(p): return p+50 def f2(p): return p*1.5 def f3(p): return p*p vars_ = (A,B,C) funcs_ = [f1, f2, f3] logic_ = ["and","or"] vol_lmt_ = [200, 300] op_ = [">","<","="] I want generate the assert code string for eval() to test the validity, take below one for example: "f1(A)>200 and f1(B)>200 and f1(C)>200" # True -^-------------^-------------^------------: funcs_ ----^-------------^-------------^---------: vars_ ------^-------------^-------------^-------: op_ ----

Calling a function by a string in JavaScript and staying in scope

≡放荡痞女 提交于 2020-01-24 01:22:29
问题 I've been playing around and searching a bit, but I can't figure this out. I have a pseudo private function within a JavaScript object that needs to get called via eval (because the name of the function is built dynamically). However, the function is hidden from the global scope by a closure and I cannot figure out how to reference it using eval(). Ex: var myObject = function(){ var privateFunctionNeedsToBeCalled = function() { alert('gets here'); }; return { publicFunction: function

Dynamic scoping questions in R

和自甴很熟 提交于 2020-01-22 15:08:45
问题 I'm reading the AdvancedR by Hadley and am testing the following code on this URL subset2 = function(df, condition){ condition_call = eval(substitute(condition),df ) df[condition_call,] } df = data.frame(a = 1:10, b = 2:11) condition = 3 subset2(df, a < condition) Then I got the following error message: Error in eval(substitute(condition), df) : object 'a' not found I read the explanation as follows but don't quite understand: If eval() can’t find the variable inside the data frame (its

Convert string to class name without using eval in ruby?

孤人 提交于 2020-01-21 03:02:30
问题 I have something like this: string = "Post" I would like to convert the string to a class name literal. I use eval like this to convert the string: eval(string) #=> Post Being a javaScript developer I try to avoid eval. Is there a better way of doing this in Ruby? Or is using eval the preferred way of handling this? 回答1: You can try class Post end Object.const_get("Post") Which returns the Post class 回答2: Use Module.const_get string = "Fixnum" clazz = Object.const_get(string) clazz.name # =>

ImplementIon of eval() in Java [duplicate]

一世执手 提交于 2020-01-20 10:09:06
问题 This question already has answers here : Is there an eval() function in Java? (12 answers) Closed 6 years ago . My question has to do with the phenomenon of non existence of function eval() in Java. After a bit of reading on the Internet I found out that the best thing I could do is to create my own parser as a Java function. But how to do that? What I need actually is a function that reads the first column of the above array and returns one after another all these values. Note however that

eval(parse(text=“f”)) on shinypass.io

China☆狼群 提交于 2020-01-17 05:01:06
问题 I want to write an app that lets the user enter a function using textInput, and then does something with the function. Here is a toy example: shinyUI(fluidPage( titlePanel("Test"), sidebarLayout( sidebarPanel( textInput("fun","function:",value="x") ), mainPanel( uiOutput("text") ) ) shinyServer(function(input, output) { findMax <- reactive({ f <- function(x) eval(parse(text = input$fun), envir = list(x)) x < seq(0,1,length=100) max(f(x)) }) output$text <- renderText( { findMax() }) }) )) and

Is there sth like `eval` in Neo4j?

爷,独闯天下 提交于 2020-01-16 09:05:33
问题 Can I evaluate cypher code from a string in Neo4j? I think about something like eval function in JavaScript. 回答1: You will be helped by the apoc library with a rich set of tools to execute the cypher from the string: call db.labels() yield label call apoc.cypher.run("match (:`"+label+"`) return count(*) as count", null) yield value return label, value.count as count 来源: https://stackoverflow.com/questions/55433173/is-there-sth-like-eval-in-neo4j

eval: why does enclos = parent.frame() make a difference?

大憨熊 提交于 2020-01-16 03:51:08
问题 In this question, the following throws an error: subset2 = function(df, condition) { condition_call = eval(substitute(condition),df ) df[condition_call,] } df = data.frame(a = 1:10, b = 2:11) condition = 3 subset2(df, a < condition) ## Error in eval(substitute(condition), df) : object 'a' not found Josh and Jason from the original question did a great job explaining why this is. What I don't get is why supplying the enclos argument to eval apparently fixes it. subset3 = function(df, condition

Is there any way, other than to use eval/handleAs: “javascript” to dynamically fetch scripts (via XMLHttpRequest)

廉价感情. 提交于 2020-01-16 01:03:10
问题 Here I have asked a question pertaining to exceptions raised when dynamically loading scripts via XMLHttpRequest (in other words when executed via eval ) In a related question, I wanted to know whether loading scripts dynamically as such is considered bad practice to begin with. In my particular case I have an HTML Canvas element, and rather than load all possible shapes, I want to fetch them dynamically, without reloading the page, and execute them on return. The problem I am having there is

Why lambda in eval function can't closure the variables in the user-defined 'locals' dict?

北城以北 提交于 2020-01-15 20:13:50
问题 I want to evaluate a lambda expression using the built-in eval function, with a variable y defined in the 'locals' argument. Sadly the result function doesn't work: >>>x = eval('lambda: print(y)',{},{'y':2}) >>>x() Traceback (most recent call last): File "<pyshell#75>", line 1, in <module> x() File "<string>", line 1, in <lambda> NameError: name 'y' is not defined But with y defined in the 'globals' argument, it does work: >>> x = eval('lambda: print(y)', {'y': 2},{}) >>> x() 2 As I

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