20.8. 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
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 ftplib
module:
>>> from ftplib import FTP
>>> ftp = FTP('ftp.debian.org') # connect to host, default port
>>> ftp.login() # user anonymous, passwd anonymous@
'230 Login successful.'
>>> ftp.cwd('debian') # change into "debian" directory
>>> 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.'
>>> ftp.retrbinary('RETR README', open('README', 'wb').write)
'226 Transfer complete.'
>>> ftp.quit()
The module defines the following items:
-
class
ftplib.
FTP
([host[, user[, passwd[, acct[, timeout]]]]])¶ Return a new instance of the
FTP
class. When host is given, the method callconnect(host)
is made. When user is given, additionally the method calllogin(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).Changed in version 2.6: timeout was added.
-
class
ftplib.
FTP_TLS
([host[, user[, passwd[, acct[, keyfile[, certfile[, context[, timeout]]]]]]]])¶ A
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 theprot_p()
method. context is assl.SSLContext
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.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.
New in version 2.7.
Changed in version 2.7.10: The context parameter was added.
Here’s a sample session using the
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
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 assocket.error
andIOError
.
See also
- 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.
The file Tools/scripts/ftpmirror.py
in the Python source distribution is
a script that can mirror FTP sites, or portions thereof, using the ftplib
module. It can be used as an extended example that applies this module.
20.8.1. 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.
FTP
instances have the following methods:
-
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 of1
produces a moderate amount of debugging output, generally a single line per request. A value of2
or higher produces the maximum amount of debugging output, logging each line sent and received on the control connection.
-
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.
Changed in version 2.6: timeout was added.
-
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.)
-
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.
-
FTP.
abort
()¶ Abort a file transfer that is in progress. Using this does not always work, but it’s worth a try.
-
FTP.
sendcmd
(command)¶ Send a simple command string to the server and return the response string.
-
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
error_reply
otherwise.
-
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 thetransfercmd()
method.
-
FTP.
retrlines
(command[, callback])¶ Retrieve a file or directory listing in ASCII transfer mode. command should be an appropriate
RETR
command (seeretrbinary()
) or a command such asLIST
,NLST
orMLSD
(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 tosys.stdout
.
-
FTP.
set_pasv
(val)¶ Enable “passive” mode if val is true, otherwise 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.)
-
FTP.
storbinary
(command, fp[, blocksize, callback, rest])¶ Store a file in binary transfer mode. command should be an appropriate
STOR
command:"STOR filename"
. fp is an open file object which is read until EOF using itsread()
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 thetransfercmd()
method.Changed in version 2.1: default for blocksize added.
Changed in version 2.6: callback parameter added.
Changed in version 2.7: rest parameter added.
-
FTP.
storlines
(command, fp[, callback])¶ Store a file in ASCII transfer mode. command should be an appropriate
STOR
command (seestorbinary()
). Lines are read until EOF from the open file object fp using itsreadline()
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.Changed in version 2.6: callback parameter added.
-
FTP.
transfercmd
(cmd[, rest])¶ Initiate a transfer over the data connection. If the transfer is active, send an
EPRT
orPORT
command and the transfer command specified by cmd, and accept the connection. If the server is passive, send anEPSV
orPASV
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. Thetransfercmd()
method, therefore, converts rest to a string, but no check is performed on the string’s contents. If the server does not recognize theREST
command, anerror_reply
exception will be raised. If this happens, simply calltransfercmd()
without a rest argument.
-
FTP.
ntransfercmd
(cmd[, rest])¶ 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 intransfercmd()
.
-
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 theNLST
command.
-
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 theLIST
command. If the last argument is a function, it is used as a callback function as forretrlines()
; the default prints tosys.stdout
. This method returnsNone
.
-
FTP.
rename
(fromname, toname)¶ Rename file fromname on the server to toname.
-
FTP.
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 orerror_reply
on other errors.
-
FTP.
cwd
(pathname)¶ Set the current directory on the server.
-
FTP.
mkd
(pathname)¶ Create a new directory on the server.
-
FTP.
pwd
()¶ Return the pathname of the current directory on the server.
-
FTP.
rmd
(dirname)¶ Remove the directory named dirname on the server.
-
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 theSIZE
command is not standardized, but is supported by many common server implementations.
-
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 theQUIT
command. This implies a call to theclose()
method which renders theFTP
instance useless for subsequent calls (see below).
-
FTP.
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 theFTP
instance should not be used any more (after a call toclose()
orquit()
you cannot reopen the connection by issuing anotherlogin()
method).
20.8.2. FTP_TLS Objects¶
FTP_TLS
class inherits from FTP
, defining these additional objects:
-
FTP_TLS.
ssl_version
¶ The SSL version to use (defaults to
ssl.PROTOCOL_SSLv23
).
-
FTP_TLS.
auth
()¶ Set up secure control connection by using TLS or SSL, depending on what specified in
ssl_version()
attribute.
-
FTP_TLS.
prot_p
()¶ Set up secure data connection.
-
FTP_TLS.
prot_c
()¶ Set up clear text data connection.