Assuming no header in the CSV file: import pandas import random n = 1000000 #number of records in file s = 10000 #desired sample size filename = “data.txt” skip = sorted(random.sample(range(n),n-s)) df = pandas.read_csv(filename, skiprows=skip) would be better if read_csv had a keeprows, or if skiprows took a callback func instead of a list. With … Read more
Assuming no header in the CSV file: import pandas import random n = 1000000 #number of records in file s = 10000 #desired sample size filename = “data.txt” skip = sorted(random.sample(range(n),n-s)) df = pandas.read_csv(filename, skiprows=skip) would be better if read_csv had a keeprows, or if skiprows took a callback func instead of a list. With … Read more
The program will not work properly because at Line 1, when the user presses Enter, it will leave in the input buffer 2 character: Enter key (ASCII code 13) and \n (ASCII code 10). Therefore, at Line 2, it will read the \n and will not wait for the user to enter a character. The … Read more
The problem was the notify filters. The program was trying to open a file that was still copying. I removed all of the notify filters except for LastWrite. private void watch() { FileSystemWatcher watcher = new FileSystemWatcher(); watcher.Path = path; watcher.NotifyFilter = NotifyFilters.LastWrite; watcher.Filter = “*.*”; watcher.Changed += new FileSystemEventHandler(OnChanged); watcher.EnableRaisingEvents = true; }
Relative paths are relative to current working directory. If you do not want your path to be relative, it must be absolute. But there is an often used trick to build an absolute path from current script: use its __file__ special attribute: from pathlib import Path path = Path(__file__).parent / “../data/test.csv” with path.open() as f: … Read more
This is because ghci disables buffering, while a program compiled with ghc has line buffering by default. You can see this by running this: import System.IO main = print =<< hGetBuffering stdout In ghci you see NoBuffering while with runghc you get LineBuffering. Since the newline character doesn’t print until after the user input, the … Read more
Drop the leading slash on relativePath and it should work. The reason why this happens is that Path.Combine is interpreting relativePath as a rooted (absolute) path because, in this case, it begins with a \. You can check if a path is relative or rooted by using Path.IsRooted(). From the doc: If the one of … Read more
df.drop(colname, axis=1) (or del df[colname]) is the correct method to use to delete a column. If a ValueError is raised, it means the column name is not exactly what you think it is. Check df.columns to see what Pandas thinks are the names of the columns.
How about this :- std::ifstream inFile(“file”); std::count(std::istreambuf_iterator<char>(inFile), std::istreambuf_iterator<char>(), ‘\n’);
The file is already closed (when the previous with block finishes), so you cannot do anything more to the file. To reopen the file, create another with statement and use the read attribute to read the file. with open(‘test_output.txt’, ‘r’) as f2: data = f2.read() print(data)