luigi.contrib.hdfs.target

Provides access to HDFS using the HdfsTarget, a subclass of Target.

Classes

HdfsFlagTarget(path[, format, client, flag])	Defines a target directory with a flag-file (defaults to _SUCCESS) used to signify job success.
HdfsTarget([path, format, is_tmp, fs])	Initializes a FileSystemTarget instance.

class luigi.contrib.hdfs.target.HdfsTarget(path=None, format=None, is_tmp=False, fs=None)

Initializes a FileSystemTarget instance.

Parameters:

path – the path associated with this FileSystemTarget.

property fs

The FileSystem associated with this FileSystemTarget.

glob_exists(expected_files)

open(mode='r')

Open the FileSystem target.

This method returns a file-like object which can either be read from or written to depending on the specified mode.

Parameters:

mode (str) – the mode r opens the FileSystemTarget in read-only mode, whereas w will open the FileSystemTarget in write mode. Subclasses can implement additional options. Using b is not supported; initialize with format=Nop instead.

remove(skip_trash=False)

Remove the resource at the path specified by this FileSystemTarget.

This method is implemented by using fs.

rename(path, raise_if_exists=False)

Does not change self.path.

Unlike move_dir(), rename() might cause nested directories. See spotify/luigi#522

move(path, raise_if_exists=False)

Alias for rename()

move_dir(path)

Move using rename_dont_move

New since after luigi v2.1: Does not change self.path

One could argue that the implementation should use the mkdir+raise_if_exists approach, but we at Spotify have had more trouble with that over just using plain mv. See spotify/luigi#557

copy(dst_dir)

Copy to destination directory.

is_writable()

Currently only works with hadoopcli

class luigi.contrib.hdfs.target.HdfsFlagTarget(path, format=None, client=None, flag='_SUCCESS')

Defines a target directory with a flag-file (defaults to _SUCCESS) used to signify job success.

This checks for two things:

• the path exists (just like the HdfsTarget)

• the _SUCCESS file exists within the directory.

Because Hadoop outputs into a directory and not a single file, the path is assumed to be a directory.

Initializes a HdfsFlagTarget.

Parameters:

• path (str) – the directory where the files are stored.

• client

• flag (str)

exists()

Returns True if the path for this FileSystemTarget exists; False otherwise.

This method is implemented by using fs.