11.5.1 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:
- 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.
- connect (host[, port])
Connect to the given host and port. The default port number is
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.
- 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[, 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', the default passwd is
"realuser@host" where realuser is the real user
name (glanced from the $LOGNAME or $USER environment
variable) and host is the hostname as returned by
socket.gethostname(). 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.
- abort ()
Abort a file transfer that is in progress. Using this does not always
work, but it's worth a try.
- sendcmd (command)
Send a simple command string to the server and return the response
- 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.
- retrbinary (command,
callback[, maxblocksize[, rest]])
Retrieve a file in binary transfer mode. command should be an
appropriate "RETR" command, i.e.
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 transfercmd() method.
- retrlines (command[, callback])
Retrieve a file or directory listing in ASCII transfer mode.
command should be an appropriate "RETR" command (see
retrbinary() or a "LIST" command (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
- set_pasv (boolean)
Enable ``passive'' mode if boolean is true, other disable
- storbinary (command, file, blocksize)
Store a file in binary transfer mode. command should be an
appropriate "STOR" command, i.e.
file is an open file object which is read until EOF using its
read() method in blocks of size blocksize to provide the
data to be stored.
- storlines (command, file)
Store a file in ASCII transfer mode. command should be an
appropriate "STOR" command (see storbinary()). Lines are
read until EOF from the open file object file using its
readline() method to provide the data to be stored.
- transfercmd (cmd[, rest])
Initiate a transfer over the data connection. If the transfer is
active, send a "PORT" command and the transfer command specified
by cmd, and accept the connection. If the server is passive,
send a "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
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
error_reply exception will be raised. If this happens,
simply call transfercmd() without a rest argument.
- 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 in
- 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.
- 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
sys.stdout. This method returns
- 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 of the server reponds 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 (e.g. after a successful call to
quit(). After this call the FTP instance should not
be used any more (i.e., after a call to close() or
quit() you cannot reopen the connection by issuing another
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