sourceReads a table from a text file or a directory of text files. The resulting table
will consist of a single column data, and have the number of rows equal to the number
of lines in the file. Each cell will contain a single line from the file.
In case the folder is specified, and there are several files placed in the folder,
their order is determined according to their modification times: the smaller the
modification time is, the earlier the file will be passed to the engine.
import pathway as pw
t = pw.io.plaintext.read("raw_dataset/lines.txt")