/Doc/library/ftplib.rst
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- :mod:`ftplib` --- FTP protocol client
- =====================================
- .. module:: ftplib
- :synopsis: FTP protocol client (requires sockets).
- .. index::
- pair: FTP; protocol
- single: FTP; ftplib (standard module)
- 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.
- .. attribute:: 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 below as well as :exc:`socket.error` and
- :exc:`IOError`.
- .. exception:: error_reply
- Exception raised when an unexpected reply is received from the server.
- .. exception:: error_temp
- Exception raised when an error code in the range 400--499 is received.
- .. exception:: error_perm
- Exception raised when an error code in the range 500--599 is received.
- .. exception:: error_proto
- Exception raised when a reply is received from the server that does not
- begin with a digit in the range 1--5.
- .. 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.
- .. 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 in the range 200--299 is received. Raise an exception
- 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'``). The *callback* function is called for each 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])
- 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.
- .. versionchanged:: 2.1
- default for *blocksize* added.
- .. versionchanged:: 2.6
- *callback* 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 files 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:`quit`. After this
- call the :class:`FTP` instance should not be used any more (after a call to
- :meth:`close` or :meth:`quit` you cannot reopen the connection by issuing
- another :meth:`login` method).