:mod:`ftplib` --- FTP protocol client
=====================================
.. module:: ftplib
:synopsis: FTP protocol client (requires sockets).
.. index::
pair: FTP; protocol
single: FTP; ftplib (standard module)
**Source code:** :source:`Lib/ftplib.py`
--------------
This module defines the class :class:`FTP` and a few related items. The
:class:`FTP` class implements the client side of the FTP protocol. You can use
this to write Python programs that perform a variety of automated FTP jobs, such
as mirroring other ftp servers. It is also used by the module :mod:`urllib` to
handle URLs that use FTP. For more information on FTP (File Transfer Protocol),
see Internet :rfc:`959`.
Here's a sample session using the :mod:`ftplib` module::
>>> from ftplib import FTP
>>> ftp = FTP('ftp.cwi.nl') # connect to host, default port
>>> ftp.login() # user anonymous, passwd anonymous@
>>> ftp.retrlines('LIST') # list directory contents
total 24418
drwxrwsr-x 5 ftp-usr pdmaint 1536 Mar 20 09:48 .
dr-xr-srwt 105 ftp-usr pdmaint 1536 Mar 21 14:32 ..
-rw-r--r-- 1 ftp-usr pdmaint 5305 Mar 20 09:48 INDEX
.
.
.
>>> ftp.retrbinary('RETR README', open('README', 'wb').write)
'226 Transfer complete.'
>>> ftp.quit()
The module defines the following items:
.. class:: FTP([host[, user[, passwd[, acct[, timeout]]]]])
Return a new instance of the :class:`FTP` class. When *host* is given, the
method call ``connect(host)`` is made. When *user* is given, additionally
the method call ``login(user, passwd, acct)`` is made (where *passwd* and
*acct* default to the empty string when not given). The optional *timeout*
parameter specifies a timeout in seconds for blocking operations like the
connection attempt (if is not specified, the global default timeout setting
will be used).
.. versionchanged:: 2.6
*timeout* was added.
.. class:: FTP_TLS([host[, user[, passwd[, acct[, keyfile[, certfile[, timeout]]]]]]])
A :class:`FTP` subclass which adds TLS support to FTP as described in
:rfc:`4217`.
Connect as usual to port 21 implicitly securing the FTP control connection
before authenticating. Securing the data connection requires the user to
explicitly ask for it by calling the :meth:`prot_p` method.
*keyfile* and *certfile* are optional -- they can contain a PEM formatted
private key and certificate chain file name for the SSL connection.
.. versionadded:: 2.7
Here's a sample session using the :class:`FTP_TLS` class:
>>> from ftplib import FTP_TLS
>>> ftps = FTP_TLS('ftp.python.org')
>>> ftps.login() # login anonymously before securing control channel
>>> ftps.prot_p() # switch to secure data connection
>>> ftps.retrlines('LIST') # list directory content securely
total 9
drwxr-xr-x 8 root wheel 1024 Jan 3 1994 .
drwxr-xr-x 8 root wheel 1024 Jan 3 1994 ..
drwxr-xr-x 2 root wheel 1024 Jan 3 1994 bin
drwxr-xr-x 2 root wheel 1024 Jan 3 1994 etc
d-wxrwxr-x 2 ftp wheel 1024 Sep 5 13:43 incoming
drwxr-xr-x 2 root wheel 1024 Nov 17 1993 lib
drwxr-xr-x 6 1094 wheel 1024 Sep 13 19:07 pub
drwxr-xr-x 3 root wheel 1024 Jan 3 1994 usr
-rw-r--r-- 1 root root 312 Aug 1 1994 welcome.msg
'226 Transfer complete.'
>>> ftps.quit()
>>>
.. exception:: error_reply
Exception raised when an unexpected reply is received from the server.
.. exception:: error_temp
Exception raised when an error code signifying a temporary error (response
codes in the range 400--499) is received.
.. exception:: error_perm
Exception raised when an error code signifying a permanent error (response
codes in the range 500--599) is received.
.. exception:: error_proto
Exception raised when a reply is received from the server that does not fit
the response specifications of the File Transfer Protocol, i.e. begin with a
digit in the range 1--5.
.. data:: all_errors
The set of all exceptions (as a tuple) that methods of :class:`FTP`
instances may raise as a result of problems with the FTP connection (as
opposed to programming errors made by the caller). This set includes the
four exceptions listed above as well as :exc:`socket.error` and
:exc:`IOError`.
.. seealso::
Module :mod:`netrc`
Parser for the :file:`.netrc` file format. The file :file:`.netrc` is
typically used by FTP clients to load user authentication information
before prompting the user.
.. index:: single: ftpmirror.py
The file :file:`Tools/scripts/ftpmirror.py` in the Python source distribution is
a script that can mirror FTP sites, or portions thereof, using the :mod:`ftplib`
module. It can be used as an extended example that applies this module.
.. _ftp-objects:
FTP Objects
-----------
Several methods are available in two flavors: one for handling text files and
another for binary files. These are named for the command which is used
followed by ``lines`` for the text version or ``binary`` for the binary version.
:class:`FTP` instances have the following methods:
.. method:: FTP.set_debuglevel(level)
Set the instance's debugging level. This controls the amount of debugging
output printed. The default, ``0``, produces no debugging output. A value of
``1`` produces a moderate amount of debugging output, generally a single line
per request. A value of ``2`` or higher produces the maximum amount of
debugging output, logging each line sent and received on the control connection.
.. method:: FTP.connect(host[, port[, timeout]])
Connect to the given host and port. The default port number is ``21``, as
specified by the FTP protocol specification. It is rarely needed to specify a
different port number. This function should be called only once for each
instance; it should not be called at all if a host was given when the instance
was created. All other methods can only be used after a connection has been
made.
The optional *timeout* parameter specifies a timeout in seconds for the
connection attempt. If no *timeout* is passed, the global default timeout
setting will be used.
.. versionchanged:: 2.6
*timeout* was added.
.. method:: FTP.getwelcome()
Return the welcome message sent by the server in reply to the initial
connection. (This message sometimes contains disclaimers or help information
that may be relevant to the user.)
.. method:: FTP.login([user[, passwd[, acct]]])
Log in as the given *user*. The *passwd* and *acct* parameters are optional and
default to the empty string. If no *user* is specified, it defaults to
``'anonymous'``. If *user* is ``'anonymous'``, the default *passwd* is
``'anonymous@'``. This function should be called only once for each instance,
after a connection has been established; it should not be called at all if a
host and user were given when the instance was created. Most FTP commands are
only allowed after the client has logged in. The *acct* parameter supplies
"accounting information"; few systems implement this.
.. method:: FTP.abort()
Abort a file transfer that is in progress. Using this does not always work, but
it's worth a try.
.. method:: FTP.sendcmd(command)
Send a simple command string to the server and return the response string.
.. method:: FTP.voidcmd(command)
Send a simple command string to the server and handle the response. Return
nothing if a response code corresponding to success (codes in the range
200--299) is received. Raise :exc:`error_reply` otherwise.
.. method:: FTP.retrbinary(command, callback[, maxblocksize[, rest]])
Retrieve a file in binary transfer mode. *command* should be an appropriate
``RETR`` command: ``'RETR filename'``. The *callback* function is called for
each block of data received, with a single string argument giving the data
block. The optional *maxblocksize* argument specifies the maximum chunk size to
read on the low-level socket object created to do the actual transfer (which
will also be the largest size of the data blocks passed to *callback*). A
reasonable default is chosen. *rest* means the same thing as in the
:meth:`transfercmd` method.
.. method:: FTP.retrlines(command[, callback])
Retrieve a file or directory listing in ASCII transfer mode. *command*
should be an appropriate ``RETR`` command (see :meth:`retrbinary`) or a
command such as ``LIST``, ``NLST`` or ``MLSD`` (usually just the string
``'LIST'``). ``LIST`` retrieves a list of files and information about those files.
``NLST`` retrieves a list of file names. On some servers, ``MLSD`` retrieves
a machine readable list of files and information about those files. The *callback*
function is called for each line with a string argument containing the line with
the trailing CRLF stripped. The default *callback* prints the line to ``sys.stdout``.
.. method:: FTP.set_pasv(boolean)
Enable "passive" mode if *boolean* is true, other disable passive mode. (In
Python 2.0 and before, passive mode was off by default; in Python 2.1 and later,
it is on by default.)
.. method:: FTP.storbinary(command, file[, blocksize, callback, rest])
Store a file in binary transfer mode. *command* should be an appropriate
``STOR`` command: ``"STOR filename"``. *file* is an open file object which is
read until EOF using its :meth:`read` method in blocks of size *blocksize* to
provide the data to be stored. The *blocksize* argument defaults to 8192.
*callback* is an optional single parameter callable that is called
on each block of data after it is sent. *rest* means the same thing as in
the :meth:`transfercmd` method.
.. versionchanged:: 2.1
default for *blocksize* added.
.. versionchanged:: 2.6
*callback* parameter added.
.. versionchanged:: 2.7
*rest* parameter added.
.. method:: FTP.storlines(command, file[, callback])
Store a file in ASCII transfer mode. *command* should be an appropriate
``STOR`` command (see :meth:`storbinary`). Lines are read until EOF from the
open file object *file* using its :meth:`readline` method to provide the data to
be stored. *callback* is an optional single parameter callable
that is called on each line after it is sent.
.. versionchanged:: 2.6
*callback* parameter added.
.. method:: FTP.transfercmd(cmd[, rest])
Initiate a transfer over the data connection. If the transfer is active, send a
``EPRT`` or ``PORT`` command and the transfer command specified by *cmd*, and
accept the connection. If the server is passive, send a ``EPSV`` or ``PASV``
command, connect to it, and start the transfer command. Either way, return the
socket for the connection.
If optional *rest* is given, a ``REST`` command is sent to the server, passing
*rest* as an argument. *rest* is usually a byte offset into the requested file,
telling the server to restart sending the file's bytes at the requested offset,
skipping over the initial bytes. Note however that RFC 959 requires only that
*rest* be a string containing characters in the printable range from ASCII code
33 to ASCII code 126. The :meth:`transfercmd` method, therefore, converts
*rest* to a string, but no check is performed on the string's contents. If the
server does not recognize the ``REST`` command, an :exc:`error_reply` exception
will be raised. If this happens, simply call :meth:`transfercmd` without a
*rest* argument.
.. method:: FTP.ntransfercmd(cmd[, rest])
Like :meth:`transfercmd`, but returns a tuple of the data connection and the
expected size of the data. If the expected size could not be computed, ``None``
will be returned as the expected size. *cmd* and *rest* means the same thing as
in :meth:`transfercmd`.
.. method:: FTP.nlst(argument[, ...])
Return a list of file names as returned by the ``NLST`` command. The
optional *argument* is a directory to list (default is the current server
directory). Multiple arguments can be used to pass non-standard options to
the ``NLST`` command.
.. method:: FTP.dir(argument[, ...])
Produce a directory listing as returned by the ``LIST`` command, printing it to
standard output. The optional *argument* is a directory to list (default is the
current server directory). Multiple arguments can be used to pass non-standard
options to the ``LIST`` command. If the last argument is a function, it is used
as a *callback* function as for :meth:`retrlines`; the default prints to
``sys.stdout``. This method returns ``None``.
.. method:: FTP.rename(fromname, toname)
Rename file *fromname* on the server to *toname*.
.. method:: FTP.delete(filename)
Remove the file named *filename* from the server. If successful, returns the
text of the response, otherwise raises :exc:`error_perm` on permission errors or
:exc:`error_reply` on other errors.
.. method:: FTP.cwd(pathname)
Set the current directory on the server.
.. method:: FTP.mkd(pathname)
Create a new directory on the server.
.. method:: FTP.pwd()
Return the pathname of the current directory on the server.
.. method:: FTP.rmd(dirname)
Remove the directory named *dirname* on the server.
.. method:: FTP.size(filename)
Request the size of the file named *filename* on the server. On success, the
size of the file is returned as an integer, otherwise ``None`` is returned.
Note that the ``SIZE`` command is not standardized, but is supported by many
common server implementations.
.. method:: FTP.quit()
Send a ``QUIT`` command to the server and close the connection. This is the
"polite" way to close a connection, but it may raise an exception if the server
responds with an error to the ``QUIT`` command. This implies a call to the
:meth:`close` method which renders the :class:`FTP` instance useless for
subsequent calls (see below).
.. method:: FTP.close()
Close the connection unilaterally. This should not be applied to an already
closed connection such as after a successful call to :meth:`~FTP.quit`.
After this call the :class:`FTP` instance should not be used any more (after
a call to :meth:`close` or :meth:`~FTP.quit` you cannot reopen the
connection by issuing another :meth:`login` method).
FTP_TLS Objects
---------------
:class:`FTP_TLS` class inherits from :class:`FTP`, defining these additional objects:
.. attribute:: FTP_TLS.ssl_version
The SSL version to use (defaults to *TLSv1*).
.. method:: FTP_TLS.auth()
Set up secure control connection by using TLS or SSL, depending on what specified in :meth:`ssl_version` attribute.
.. method:: FTP_TLS.prot_p()
Set up secure data connection.
.. method:: FTP_TLS.prot_c()
Set up clear text data connection.
|
