"ftplib" --- FTP protocol client
********************************

**Source code:** Lib/ftplib.py

======================================================================

This module defines the class "FTP" and a few related items. The "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 "urllib.request" to handle URLs that use FTP.  For more
information on FTP (File Transfer Protocol), see internet **RFC 959**.

The default encoding is UTF-8, following **RFC 2640**.

Availability: not Emscripten, not WASI.

This module does not work or is not available on WebAssembly platforms
"wasm32-emscripten" and "wasm32-wasi". See WebAssembly platforms for
more information.

Here's a sample session using the "ftplib" module:

   >>> from ftplib import FTP
   >>> ftp = FTP('ftp.us.debian.org')  # connect to host, default port
   >>> ftp.login()                     # user anonymous, passwd anonymous@
   '230 Login successful.'
   >>> ftp.cwd('debian')               # change into "debian" directory
   '250 Directory successfully changed.'
   >>> ftp.retrlines('LIST')           # list directory contents
   -rw-rw-r--    1 1176     1176         1063 Jun 15 10:18 README
   ...
   drwxr-sr-x    5 1176     1176         4096 Dec 19  2000 pool
   drwxr-sr-x    4 1176     1176         4096 Nov 17  2008 project
   drwxr-xr-x    3 1176     1176         4096 Oct 10  2012 tools
   '226 Directory send OK.'
   >>> with open('README', 'wb') as fp:
   >>>     ftp.retrbinary('RETR README', fp.write)
   '226 Transfer complete.'
   >>> ftp.quit()
   '221 Goodbye.'


Reference
=========


FTP objects
-----------

class ftplib.FTP(host='', user='', passwd='', acct='', timeout=None, source_address=None, *, encoding='utf-8')

   Return a new instance of the "FTP" class.

   Parametri:
      * **host** (*str*) -- The hostname to connect to. If given,
        "connect(host)" is implicitly called by the constructor.

      * **user** (*str*) -- The username to log in with (default:
        "'anonymous'"). If given, "login(host, passwd, acct)" is
        implicitly called by the constructor.

      * **passwd** (*str*) -- The password to use when logging in. If
        not given, and if *passwd* is the empty string or ""-"", a
        password will be automatically generated.

      * **acct** (*str*) -- Account information to be used for the
        "ACCT" FTP command. Few systems implement this. See RFC-959
        for more details.

      * **timeout** (*float** | **None*) -- A timeout in seconds for
        blocking operations like "connect()" (default: the global
        default timeout setting).

      * **source_address** (*tuple** | **None*) -- A 2-tuple "(host,
        port)" for the socket to bind to as its source address before
        connecting.

      * **encoding** (*str*) -- The encoding for directories and
        filenames (default: "'utf-8'").

   The "FTP" class supports the "with" statement, e.g.:

   >>> from ftplib import FTP
   >>> with FTP("ftp1.at.proftpd.org") as ftp:
   ...     ftp.login()
   ...     ftp.dir()
   ... 
   '230 Anonymous login ok, restrictions apply.'
   dr-xr-xr-x   9 ftp      ftp           154 May  6 10:43 .
   dr-xr-xr-x   9 ftp      ftp           154 May  6 10:43 ..
   dr-xr-xr-x   5 ftp      ftp          4096 May  6 10:43 CentOS
   dr-xr-xr-x   3 ftp      ftp            18 Jul 10  2008 Fedora
   >>>

   Cambiato nella versione 3.2: Support for the "with" statement was
   added.

   Cambiato nella versione 3.3: *source_address* parameter was added.

   Cambiato nella versione 3.9: If the *timeout* parameter is set to
   be zero, it will raise a "ValueError" to prevent the creation of a
   non-blocking socket. The *encoding* parameter was added, and the
   default was changed from Latin-1 to UTF-8 to follow **RFC 2640**.

   Several "FTP" methods are available in two flavors: one for
   handling text files and another for binary files. The methods are
   named for the command which is used followed by "lines" for the
   text version or "binary" for the binary version.

   "FTP" instances have the following methods:

   set_debuglevel(level)

      Set the instance's debugging level as an "int". This controls
      the amount of debugging output printed. The debug levels are:

      * "0" (default): No debug output.

      * "1": Produce a moderate amount of debug output, generally a
        single line per request.

      * "2" or higher: Produce the maximum amount of debugging output,
        logging each line sent and received on the control connection.

   connect(host='', port=0, timeout=None, source_address=None)

      Connect to the given host and port. This function should be
      called only once for each instance; it should not be called if a
      *host* argument was given when the "FTP" instance was created.
      All other "FTP" methods can only be called after a connection
      has successfully been made.

      Parametri:
         * **host** (*str*) -- The host to connect to.

         * **port** (*int*) -- The TCP port to connect to (default:
           "21", as specified by the FTP protocol specification). It
           is rarely needed to specify a different port number.

         * **timeout** (*float** | **None*) -- A timeout in seconds
           for the connection attempt (default: the global default
           timeout setting).

         * **source_address** (*tuple** | **None*) -- A 2-tuple
           "(host, port)" for the socket to bind to as its source
           address before connecting.

      Raises an auditing event "ftplib.connect" with arguments "self",
      "host", "port".

      Cambiato nella versione 3.3: *source_address* parameter was
      added.

   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.)

   login(user='anonymous', passwd='', acct='')

      Log on to the connected FTP server. This function should be
      called only once for each instance, after a connection has been
      established; it should not be called if the *host* and *user*
      arguments were given when the "FTP" instance was created. Most
      FTP commands are only allowed after the client has logged in.

      Parametri:
         * **user** (*str*) -- The username to log in with (default:
           "'anonymous'").

         * **passwd** (*str*) -- The password to use when logging in.
           If not given, and if *passwd* is the empty string or ""-"",
           a password will be automatically generated.

         * **acct** (*str*) -- Account information to be used for the
           "ACCT" FTP command. Few systems implement this. See RFC-959
           for more details.

   abort()

      Abort a file transfer that is in progress.  Using this does not
      always work, but it's worth a try.

   sendcmd(cmd)

      Send a simple command string to the server and return the
      response string.

      Raises an auditing event "ftplib.sendcmd" with arguments "self",
      "cmd".

   voidcmd(cmd)

      Send a simple command string to the server and handle the
      response.  Return the response string if the response code
      corresponds to success (codes in the range 200--299).  Raise
      "error_reply" otherwise.

      Raises an auditing event "ftplib.sendcmd" with arguments "self",
      "cmd".

   retrbinary(cmd, callback, blocksize=8192, rest=None)

      Retrieve a file in binary transfer mode.

      Parametri:
         * **cmd** (*str*) -- An appropriate "STOR" command: ""STOR
           *filename*"".

         * **callback** (*callable*) -- A single parameter callable
           that is called for each block of data received, with its
           single argument being the data as "bytes".

         * **blocksize** (*int*) -- The maximum chunk size to read on
           the low-level "socket" object created to do the actual
           transfer. This also corresponds to the largest size of data
           that will be passed to *callback*. Defaults to "8192".

         * **rest** (*int*) -- A "REST" command to be sent to the
           server. See the documentation for the *rest* parameter of
           the "transfercmd()" method.

   retrlines(cmd, callback=None)

      Retrieve a file or directory listing in the encoding specified
      by the *encoding* parameter at initialization. *cmd* should be
      an appropriate "RETR" command (see "retrbinary()") or a command
      such as "LIST" or "NLST" (usually just the string "'LIST'").
      "LIST" retrieves a list of files and information about those
      files. "NLST" retrieves a list of file names. 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".

   set_pasv(val)

      Enable "passive" mode if *val* is true, otherwise disable
      passive mode. Passive mode is on by default.

   storbinary(cmd, fp, blocksize=8192, callback=None, rest=None)

      Store a file in binary transfer mode.

      Parametri:
         * **cmd** (*str*) -- An appropriate "STOR" command: ""STOR
           *filename*"".

         * **fp** (*file object*) -- A file object (opened in binary
           mode) which is read until EOF, using its "read()" method in
           blocks of size *blocksize* to provide the data to be
           stored.

         * **blocksize** (*int*) -- The read block size. Defaults to
           "8192".

         * **callback** (*callable*) -- A single parameter callable
           that is called for each block of data sent, with its single
           argument being the data as "bytes".

         * **rest** (*int*) -- A "REST" command to be sent to the
           server. See the documentation for the *rest* parameter of
           the "transfercmd()" method.

      Cambiato nella versione 3.2: The *rest* parameter was added.

   storlines(cmd, fp, callback=None)

      Store a file in line mode.  *cmd* should be an appropriate
      "STOR" command (see "storbinary()").  Lines are read until EOF
      from the *file object* *fp* (opened in binary mode) using its
      "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.

   transfercmd(cmd, rest=None)

      Initiate a transfer over the data connection.  If the transfer
      is active, send an "EPRT" or  "PORT" command and the transfer
      command specified by *cmd*, and accept the connection.  If the
      server is passive, send an "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 the "transfercmd()" method
      converts *rest* to a string with the *encoding* parameter
      specified at initialization, but no check is performed on the
      string's contents.  If the server does not recognize the "REST"
      command, an "error_reply" exception will be raised.  If this
      happens, simply call "transfercmd()" without a *rest* argument.

   ntransfercmd(cmd, rest=None)

      Like "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 "transfercmd()".

   mlsd(path='', facts=[])

      List a directory in a standardized format by using "MLSD"
      command (**RFC 3659**).  If *path* is omitted the current
      directory is assumed. *facts* is a list of strings representing
      the type of information desired (e.g. "["type", "size",
      "perm"]").  Return a generator object yielding a tuple of two
      elements for every file found in path.  First element is the
      file name, the second one is a dictionary containing facts about
      the file name.  Content of this dictionary might be limited by
      the *facts* argument but server is not guaranteed to return all
      requested facts.

      Nuovo nella versione 3.3.

   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.

      Nota:

        If your server supports the command, "mlsd()" offers a better
        API.

   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 "retrlines()"; the default
      prints to "sys.stdout".  This method returns "None".

      Nota:

        If your server supports the command, "mlsd()" offers a better
        API.

   rename(fromname, toname)

      Rename file *fromname* on the server to *toname*.

   delete(filename)

      Remove the file named *filename* from the server.  If
      successful, returns the text of the response, otherwise raises
      "error_perm" on permission errors or "error_reply" on other
      errors.

   cwd(pathname)

      Set the current directory on the server.

   mkd(pathname)

      Create a new directory on the server.

   pwd()

      Return the pathname of the current directory on the server.

   rmd(dirname)

      Remove the directory named *dirname* on the server.

   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.

   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 "close()" method which
      renders the "FTP" instance useless for subsequent calls (see
      below).

   close()

      Close the connection unilaterally.  This should not be applied
      to an already closed connection such as after a successful call
      to "quit()". After this call the "FTP" instance should not be
      used any more (after a call to "close()" or "quit()" you cannot
      reopen the connection by issuing another "login()" method).


FTP_TLS objects
---------------

class ftplib.FTP_TLS(host='', user='', passwd='', acct='', keyfile=None, certfile=None, context=None, timeout=None, source_address=None, *, encoding='utf-8')

   An "FTP" subclass which adds TLS support to FTP as described in
   **RFC 4217**. Connect to port 21 implicitly securing the FTP
   control connection before authenticating.

   Nota:

     The user must explicitly secure the data connection by calling
     the "prot_p()" method.

   Parametri:
      * **host** (*str*) -- The hostname to connect to. If given,
        "connect(host)" is implicitly called by the constructor.

      * **user** (*str*) -- The username to log in with (default:
        "'anonymous'"). If given, "login(host, passwd, acct)" is
        implicitly called by the constructor.

      * **passwd** (*str*) -- The password to use when logging in. If
        not given, and if *passwd* is the empty string or ""-"", a
        password will be automatically generated.

      * **acct** (*str*) -- Account information to be used for the
        "ACCT" FTP command. Few systems implement this. See RFC-959
        for more details.

      * **context** ("ssl.SSLContext") -- An SSL context object which
        allows bundling SSL configuration options, certificates and
        private keys into a single, potentially long-lived, structure.
        Please read Security considerations for best practices.

      * **timeout** (*float** | **None*) -- A timeout in seconds for
        blocking operations like "connect()" (default: the global
        default timeout setting).

      * **source_address** (*tuple** | **None*) -- A 2-tuple "(host,
        port)" for the socket to bind to as its source address before
        connecting.

      * **encoding** (*str*) -- The encoding for directories and
        filenames (default: "'utf-8'").

   *keyfile* and *certfile* are a legacy alternative to *context* --
   they can point to PEM-formatted private key and certificate chain
   files (respectively) for the SSL connection.

   Nuovo nella versione 3.2.

   Cambiato nella versione 3.3: Added the *source_address* parameter.

   Cambiato nella versione 3.4: The class now supports hostname check
   with "ssl.SSLContext.check_hostname" and *Server Name Indication*
   (see "ssl.HAS_SNI").

   Deprecato dalla versione 3.6: *keyfile* and *certfile* are
   deprecated in favor of *context*. Please use
   "ssl.SSLContext.load_cert_chain()" instead, or let
   "ssl.create_default_context()" select the system's trusted CA
   certificates for you.

   Cambiato nella versione 3.9: If the *timeout* parameter is set to
   be zero, it will raise a "ValueError" to prevent the creation of a
   non-blocking socket. The *encoding* parameter was added, and the
   default was changed from Latin-1 to UTF-8 to follow **RFC 2640**.

   Here's a sample session using the "FTP_TLS" class:

      >>> ftps = FTP_TLS('ftp.pureftpd.org')
      >>> ftps.login()
      '230 Anonymous user logged in'
      >>> ftps.prot_p()
      '200 Data protection level set to "private"'
      >>> ftps.nlst()
      ['6jack', 'OpenBSD', 'antilink', 'blogbench', 'bsdcam', 'clockspeed', 'djbdns-jedi', 'docs', 'eaccelerator-jedi', 'favicon.ico', 'francotone', 'fugu', 'ignore', 'libpuzzle', 'metalog', 'minidentd', 'misc', 'mysql-udf-global-user-variables', 'php-jenkins-hash', 'php-skein-hash', 'php-webdav', 'phpaudit', 'phpbench', 'pincaster', 'ping', 'posto', 'pub', 'public', 'public_keys', 'pure-ftpd', 'qscan', 'qtc', 'sharedance', 'skycache', 'sound', 'tmp', 'ucarp']

   "FTP_TLS" class inherits from "FTP", defining these additional
   methods and attributes:

   ssl_version

      The SSL version to use (defaults to "ssl.PROTOCOL_SSLv23").

   auth()

      Set up a secure control connection by using TLS or SSL,
      depending on what is specified in the "ssl_version" attribute.

      Cambiato nella versione 3.4: The method now supports hostname
      check with "ssl.SSLContext.check_hostname" and *Server Name
      Indication* (see "ssl.HAS_SNI").

   ccc()

      Revert control channel back to plaintext.  This can be useful to
      take advantage of firewalls that know how to handle NAT with
      non-secure FTP without opening fixed ports.

      Nuovo nella versione 3.3.

   prot_p()

      Set up secure data connection.

   prot_c()

      Set up clear text data connection.


Module variables
----------------

exception ftplib.error_reply

   Exception raised when an unexpected reply is received from the
   server.

exception ftplib.error_temp

   Exception raised when an error code signifying a temporary error
   (response codes in the range 400--499) is received.

exception ftplib.error_perm

   Exception raised when an error code signifying a permanent error
   (response codes in the range 500--599) is received.

exception ftplib.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.

ftplib.all_errors

   The set of all exceptions (as a tuple) that methods of "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 "OSError" and
   "EOFError".

Vedi anche:

  Module "netrc"
     Parser for the ".netrc" file format.  The file ".netrc" is
     typically used by FTP clients to load user authentication
     information before prompting the user.
