Using hdfs3 with HDFS

hdfs3 is a lightweight Python wrapper around the C/C++ libhdfs3 library. It allows us to use HDFS natively from Python. To start, we first need to connect with the HDFS NameNode; this is done using the HDFileSystem class:

from hdfs3 import HDFileSystem
hdfs = HDFileSystem(host = 'localhost', port=8020)

This automatically establishes a connection with the NameNode. Now, we can access a directory listing using the following:

print(hdfs.ls('/tmp')) 

This will list all the files and directories in the tmp folder. You can use functions such as mkdir to make a directory and cp to copy a file from one location to another. To write into a file, we open it first using the open method and use write:

with hdfs.open('/tmp/file1.txt','wb') as f:
    f.write(b'You are Awesome!')

Data can be read from the file:

with hdfs.open('/tmp/file1.txt') as f:
    print(f.read())

You can learn more about hdfs3 from its documentation: https://media.readthedocs.org/pdf/hdfs3/latest/hdfs3.pdf.