Higher-level interface to ftplib
ftplib in itself is a bit raw, as it leaves details about the protocol for
the user to handle.
ftptool abstracts that away, and even provides a neat
interface for file management.
Connecting & Authenticating
Code says more than words, so let’s look at an example: connecting.
>>> a_host = FTPHost.connect("ftp.python.org", user="foo", password="bar")
connect is a classmethod that lets you create an
FTPHost instance with an
Working with Directories
Changing Working Directory
Changing and getting the current directory is implemented as a property called
current_directory. It is lazy; it won’t ask the server which the current
directory is until you ask for it.
Note that since it’s a property, this will actually go one level up:
>>> a_host.current_directory = ".."
Similarly, this will descend into the “foo” directory:
>>> a_host.current_directory = "foo"
In most cases, it’s easier to just specify absolute paths:
>>> a_host.current_directory = "/foo"
current_directory will always be the server-side representation; when you
change directory, it ends up sending a CWD and then a PWD to get the
result of the operation (since the FTP protocol doesn’t define what the reply
text to a CWD is.)
Listing and Walking the Directory Tree
os.walk interface is implemented for walking the directory tree:
>>> for (dirname, subdirs, files) in a_host.walk("/a_dir"): ... print dirname, "has file(s)", ", ".join(files) ... /a_dir has file(s) foo, bar /a_dir/other_dir has file(s) hello /a_dir/some_dir has file(s)
os.walk, you can remove entries in the
subdirs list to avoid
descending into them:
>>> for (dirname, subdirs, files) in a_host.walk("/a_dir"): ... for subdir in subdirs: ... if subdir.startswith("other_"): ... subdirs.remove(subdir) ... print dirname, "has file(s)", ", ".join(files) ... /a_dir has file(s) foo, bar /a_dir/some_dir has file(s)
You can non-recursively list a directory using
>>> a_host.listdir("/a_dir") (['other_dir', 'some_dir'], ['foo', 'bar'])
Creating, Deleting and Renaming
The most simple form of creating a directory is
mkdir. You simply give it a
directory to create, and so it does:
If you just want to ascertain that a directory is ready, i.e., exists for an
upload, you could use
makedirs which tries to create every part of the
directory, piece by piece.
Would, hypothetically, create a_new_dir and other_new_dir.
ftptool implements it by first trying to change directory into the given
path, to see if it exists, and then changes back. If it does, it simply
returns, otherwise it creates the directories piece by piece.
Using the File Proxy
ftptool are implemented using proxy objects called
They represent a file on a remote host. Using them is easy as pie!
>>> a_host.file_proxy("/a_dir/foo").download_to_str() 'This is the file "foo".' >>> a_host.file_proxy("/a_dir/new_file").upload_from_str("Hello world!")
The Three Upload & Download Methods
ftptool provides three ways of uploading or downloading files:
* to/from_str: using a str object,
* to/from_file: using a filename,
* and the default: using a file-like object.
>>> f = a_host.file_proxy("/foo.txt")
You could upload and download from str using these two:
>>> f.upload_from_str("Hi!") >>> f.download_to_str() 'Hi!'
And using a filename like this:
>>> f.upload_from_file("/etc/motd") >>> f.download_to_file("/tmp/motd")
And lastly, using file-like objects:
>>> f.upload(StringIO("Test!")) >>> fp = StringIO() >>> f.download(fp) >>> fp.getvalue() 'Test!'
Renaming is a method of the file proxies, called
rename. It returns a new
file proxy for the renamed-to file, so the common pattern will be:
>>> a_file = a_host.file_proxy("hello_world") >>> a_file = a_file.rename("foobar")
This will issue a rename command, too, so
a_file will essentially be the same
as before, with a new name and a new instance ID.
Deleting a file is much like renaming it: it’s a method of the file proxies,
delete. It, however, doesn’t have a meaningful return value.
ftptool supports two types of mirroring: local to remote, and remote to
local. As in, it can download a whole directory and all descendants into a
local directory, for you to play with. It can also upload a whole directory to
a remote host.
The first one, downloading, is called
mirror_to_local. It’s used like so:
>>> a_host.mirror_to_local('/a_dir', 'my_copy_of_a_dir')
The cousin, mirror_to_remote, has the same signature; source first, then destination.
>>> a_host.mirror_to_remote('my_copy_of_a_dir', '/a_dir')
If the local working directory is the one you want to upload, you can just give
mirror_to_remote an empty string or a dot.