ggreg / python-anywhere

Overview

Anywhere provides a set of modules to work with resources that are identified by a URL. It comes with a set of handlers that can be extended.

It is licensed under a BSD 2-Clause license (see LICENSE.txt).

The Resource type

The Resource type abstracts access to a resource identified by a URL that contains:

• the protocol
• the path

>>> remote = Resource('ssh://storage1/path/to/file.json')

Every Resource implements the interface:

• path: full path without the protocol
• str returns the URL
• name
• size
• atime
• mtime
• ctime
• get()
• put()
• delete()
• read()

Examples

These examples come from the filesystem interface in anywhere.resource.handler.filesystem.

Handling a file

Let's start by importing some modules to compare the resource interface with the Python standard library:

>>> import tempfile
>>> import os.path
>>> import shutil

Now we create a temporary file and wrap it in a FileResource:

>>> tmp = tempfile.NamedTemporaryFile()
>>> file = Resource(tmp.name)
>>> file # doctest: +ELLIPSIS
<FileResource file:///tmp/tmp...>
>>> str(file) # doctest: +ELLIPSIS
'file:///tmp/tmp...'
>>> file.path == tmp.name
True
>>> file.name == os.path.basename(tmp.name)
True
>>> file.size
0

The file is currently empty. We can append a line to it to add some content:

>>> file.append('First line.')
>>> file.read()
'First line.'

We can also add several lines at the same time:

>>> file.extend(['Second line.', 'Third line.'])
>>> file.read()
'Second line.\\nThird line.'

Handling a directory

We continue by creating a temporary directory:

>>> tmpdir = tempfile.mkdtemp()
>>> dir = Resource(tmpdir)

The file is not inside:

>>> file in dir
False

Let's copy it into the directory:

>>> dir.add(file)
>>> file in dir
True
>>> list(dir) == [file.name]
True
>>> file_alias = dir[file.name]
>>> file_alias.read() == file.read()
True

By default meth:FileResource.add overwrites the file if it already exists in the directory:

    >>> dir.add(file)

Setting the parameter overwrite to False allows to prevent from overwriting the file:

>>> dir.add(file, overwrite=False) #doctest: +ELLIPSIS
Traceback (most recent call last):
...
IOError: '...' already exists in '/tmp/...'

>>> dir.remove(file)
>>> list(dir)
[]

Beware the a file alias may reference a file that was removed:

>>> file_alias.read() #doctest: +ELLIPSIS
Traceback (most recent call last):
...
IOError: [Errno 2] No such file or directory: '/tmp/...'