Question

来自Python recursively appending list function 尝试以递归方式获取与文件结构关联的权限列表。

我有这个功能：

def get_child_perms(self, folder, request, perm_list):
        # Folder contains other folders
        if folder.get_children():
            # For every sub-folder
            return [self.get_child_perms(subfolder, request, perm_list) for subfolder in folder.get_children()]
        return folder.has_read_permission(request)

返回除包含其他文件夹的文件夹以外的所有结果。

folder <- Missing (allowed)
    subfolder <- Missing (restricted)
        subsubfolder <- Get this (restricted)
            files

来自功能的输出将是 [真，假，假]

另一种情况是，A =允许，R =受限

folder  A
    subfolder   A
        subsubfolder    R
            files
        files
    subfolder   R
        files
    subfolder   A
        subsubfolder    A
            files
        files
    subfolder   A
        files
    files

输出将是 [真，TRUE，FALSE，FALSE，TRUE，TRUE，TRUE]

Answer 1

基本问题是，您只返回Where-Object，当文件夹没有任何子项时，当它有子项时，您不会在返回结果中包含using System; using System.Collections.Generic; using System.IO; using System.Linq; using System.Text; using System.Threading.Tasks; using System.Xml.Linq; namespace MergeResx { class Program { static void Main(string[] args) { var folder = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.DesktopDirectory),"resx"); var x = MergeResxFiles(new [] { Path.Combine(folder,args[0]), Path.Combine(folder, args[1])}); File.WriteAllText(Path.Combine(folder, "merged.xml"), x.ToString()); Console.WriteLine("--done--"); Console.ReadLine(); } static XDocument MergeResxFiles(string[] files) { var allResources = from f in files let doc = XDocument.Load(f) from e in doc.Root.Elements("data") select Resource.Parse(e, f); var elements = new List<XElement>(); var enumerable = allResources.GroupBy(r => r.Name).OrderBy(x=>x.Key).ToList(); foreach (var g in enumerable) { elements.AddRange(MergeResources(g.Key, g)); } Console.WriteLine("Terms: " + enumerable.Count()); var output = new XDocument(new XElement("root", elements)); return output; } private static IEnumerable<XElement> MergeResources(string name, IEnumerable<Resource> resources) { var grouped = resources.GroupBy(r => r.Value).ToList(); if (grouped.Count == 1) { yield return grouped[0].First().Xml; } else { Console.WriteLine($"Duplicate entries for {name}"); foreach (var g in grouped) { var comments = g.Select(r => new XComment($"Source: {r.FileName}")); yield return new XElement( "data", comments, new XAttribute("name", name), new XElement("value", g.Key)); } } } class Resource { public string Name { get; } public string Value { get; } public string Comment { get; } public string FileName { get; } public XElement Xml { get; } public Resource(string name, string value, string fileName,string comment, XElement xml) { Name = name; Value = value; Comment = comment; FileName = fileName; Xml = xml; } public static Resource Parse(XElement element, string fileName) { string name = element.Attribute("name").Value; string value = element.Element("value").Value; string comment = element.Element("comment")?.Value; return new Resource(name, value, fileName, comment, element); } } }，这很可能是导致你发出问题。你需要做 -

folder permission

这应该导致（未经测试） -

folder.has_read_permission(request)

Answer 2

为什么不 os.walk

当topdown为True时，调用者可以就地修改dirnames列表（可能使用del或slice赋值），而walk（）只会递归进入名称保留在dirnames中的子目录;这可以用来修剪搜索，强加一个特定的访问顺序，甚至通知walk（）有关调用者创建或重命名的目录在它再次恢复步行（）之前。自上而下修改dirnames 假是无效的，因为在自下而上模式下的目录 dirnames是在生成dirpath本身之前生成的。

例如，您可以构建仅生成非受限目录的生成器（惰性列表）

import System.IO
import System.Environment
import Control.Monad
import Data.Bits
import Data.Word
import Data.Maybe
import Data.List hiding (maximumBy)
import Data.Char
import Data.Ord
import Data.Foldable hiding (sum)


hexChars = "0123456789ABCDEF"

hexToBytes :: String -> Maybe [Word8]
{- Converts a hex string into a byte array -}

hexToBytes hexes = hexToBytes' (map toUpper hexes)
hexToBytes' (char1 : char2 : xs) = do
    tail <- hexToBytes' xs
    byte1 <- char1 `elemIndex` hexChars
    byte2 <- char2 `elemIndex` hexChars
    return ((fromIntegral(byte1*16 + byte2) :: Word8) : tail)
hexToBytes' [_] = Nothing
hexToBytes' [] = Just []

maxBy :: Ord b => Foldable f => (a -> b) -> f a -> a
maxBy = maximumBy . comparing

bytesToString :: Integral i => Monad m => m i -> m Char
bytesToString = liftM (chr . fromIntegral)  

isLowercase x = (x >= 'a') && (x <= 'z')

asciiCheck :: Word8 -> Int
asciiCheck x = if (isLowercase . chr . fromIntegral) x then 1 else 0

score = (sum . map asciiCheck)

readLines :: Handle -> IO [String]
readLines handle = do
    eof <- hIsEOF handle
    if eof then
        return []
    else liftM2 (:) (hGetLine handle) (readLines handle)

decode key = map (xor key)

keys = [minBound ..] :: [Word8]

massDecode inputs =
    maxBy score (liftM2 decode keys inputs)

main = do
    hSetEncoding stdout latin1
    args <- getArgs
    handle <- case args of
        [] -> return stdin
        (x:xs) -> openFile x ReadMode
    lines <- readLines handle
    putStrLn $ bytesToString $ massDecode $ catMaybes $ map hexToBytes lines

Python递归函数缺少结果

2 个答案: