Read a text file from HDFS, a local file system (available on all
nodes), or any Hadoop-supported file system URI, and return it as an
RDD of Strings.
The text files must be encoded as UTF-8.
If use_unicode is False, the strings will be kept as str (encoding
as utf-8), which is faster and smaller than unicode. (Added in
>>> path = os.path.join(tempdir, "sample-text.txt")
>>> with open(path, "w") as testFile:
... _ = testFile.write("Hello world!")
>>> textFile = sc.textFile(path)