io

问题 I have some strings that represent lines in a CSV: String headers = "Date,Color,Model,Price"; String line1 = "12-03-2012,Red,Toyota,13500"; I want to return a bytestream that would correspond to the corresponding csv file. I've seen how to convert csv files to strings (using InputStream and BufferedReader ), but not the reverse operation. Any help would be appreciated! 回答1: You can use String.getBytes(Charset) method for this purpose: String str = "Lorem ipsum"; byte[] arr = str.getBytes

问题 I have some strings that represent lines in a CSV: String headers = "Date,Color,Model,Price"; String line1 = "12-03-2012,Red,Toyota,13500"; I want to return a bytestream that would correspond to the corresponding csv file. I've seen how to convert csv files to strings (using InputStream and BufferedReader ), but not the reverse operation. Any help would be appreciated! 回答1: You can use String.getBytes(Charset) method for this purpose: String str = "Lorem ipsum"; byte[] arr = str.getBytes

问题 I am learning C++and I have to read a file in binary mode. Here's how I do it (following the C++ reference): unsigned values[255]; unsigned total; ifstream in ("test.txt", ifstream::binary); while(in.good()){ unsigned val = in.get(); if(in.good()){ values[val]++; total++; cout << val <<endl; } } in.close(); So, I am reading the file byte per byte till in.good() is true. I put some cout at the end of the while in order to understand what's happening, and here is the output: marco@iceland:~

问题 I would like to know is there a method that can read multiple lines from a file batch by batch. For example: with open(filename, 'rb') as f: for n_lines in f: process(n_lines) In this function, what I would like to do is: for every iteration, next n lines will be read from the file, batch by batch. Because one single file is too big. What I want to do is to read it part by part. 回答1: itertools.islice and two arg iter can be used to accomplish this, but it's a little funny: from itertools

问题 I would like to know is there a method that can read multiple lines from a file batch by batch. For example: with open(filename, 'rb') as f: for n_lines in f: process(n_lines) In this function, what I would like to do is: for every iteration, next n lines will be read from the file, batch by batch. Because one single file is too big. What I want to do is to read it part by part. 回答1: itertools.islice and two arg iter can be used to accomplish this, but it's a little funny: from itertools

问题 I am trying to understand functional programming from first principles, yet I am stuck on the interface between the pure functional world and the impure real world that has state and side effects. From a mathematical perspective, what is a function that returns a function? what is a function that returns an IO action (like Haskell's IO type)? To elaborate: In my understanding, a pure function is a map from domain to co-domain. Ultimately, it is a map from some values in computer memory to

问题 I am trying to understand functional programming from first principles, yet I am stuck on the interface between the pure functional world and the impure real world that has state and side effects. From a mathematical perspective, what is a function that returns a function? what is a function that returns an IO action (like Haskell's IO type)? To elaborate: In my understanding, a pure function is a map from domain to co-domain. Ultimately, it is a map from some values in computer memory to

问题 I'm trying to use parallel h5py to create an independent group for each process and fill each group with some data.. what happens is that only one group gets created and filled with data. This is the program: from mpi4py import MPI import h5py rank = MPI.COMM_WORLD.Get_rank() f = h5py.File('parallel_test.hdf5', 'w', driver='mpio', comm=MPI.COMM_WORLD) data = range(1000) dset = f.create_dataset(str(rank), data=data) f.close() Any thoughts on what is going wrong here? Thanks alot 回答1: Ok, so as

问题 import System.IO import Text.Printf kodable :: IO() kodable = do printf "Please load a map : " file <- getLine mapFile <- openFile file ReadMode let map = loadMap [] mapFile hClose mapFile printf "Read map successfully! \n" printf "Initial:\n" outputMap map loadMap :: [String] -> FilePath -> [String] loadMap map fp = do finished <- hIsEOF fp new_map <- if not finished then map ++ [hGetLine fp] else return () loadMap new_map fp outputMap :: [String] -> IO() outputMap (x) = printf "%s\n" x

问题 We are facing problem that camel file component readLockCheckInterval allow single file to be processed at a time and for next file camel lock, it will wait for readLockCheckInterval time. We have 10000 or more files which we want to process in parallel. I want to use maxMessagesPerPoll attribute for accessing multiple file per poll but with readLockCheckInterval because camel release the file lock if the file is still being copied. It will be great help if there will be any other way to