ftplib — FTP (文件传输协议) 客户端

源代码: Lib/ftplib.py


此模块定义类 FTP 和一些相关项。 FTP 类实现 FTP 协议的客户端侧。可以使用这编写 Python 程序履行各种自动 FTP 作业 (譬如:镜像其它 FTP 服务器)。它还可用于模块 urllib.request 以处理使用 FTP 的 URL。有关 FTP (文件传输协议) 的更多信息,见 Internet RFC 959 .

默认编码为 UTF-8,遵循 RFC 2640 .

这里的样本会话使用 ftplib 模块:

>>> 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.'
							

模块定义了下列项:

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

返回新的实例化 FTP 类。当 host 有给定,方法调用 connect(host) 产生。当 user 有给定,此外,方法调用 login(user, passwd, acct) 产生 (其中 passwd and acct 默认为空字符串当未给定时)。可选 timeout 参数指定超时 (以秒为单位) 为阻塞像连接尝试操作 (若未指定,将使用全局默认超时设置)。 source_address 是 2 元组 (host, port) 为将套接字绑定作为其源地址在连接之前。 encoding 参数指定用于目录和文件名的编码。

FTP 类支持 with 语句,如:

>>> 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
>>>
									

3.2 版改变: 支持 with 语句被添加。

3.3 版改变: source_address 参数被添加。

3.9 版改变: timeout 参数被设为 0,它将引发 ValueError 以阻止非阻塞套接字的创建。 encoding 参数被添加,且默认从 Latin-1 改为 UTF-8 遵循 RFC 2640 .

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

FTP 子类添加 TLS 支持到 FTP 作为描述在 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 prot_p() 方法。 context ssl.SSLContext 对象允许捆绑 SSL 配置选项、证书及私钥成单一 (潜在长期存活) 结构。请阅读 安全注意事项 了解最佳实践。

keyfile and certfile 是传统替代对于 context – they can point to PEM-formatted private key and certificate chain files (respectively) for the SSL connection.

3.2 版新增。

3.3 版改变: source_address 参数被添加。

3.4 版改变: 类现在支持主机名校验采用 ssl.SSLContext.check_hostname and SNI (服务器名称指示) (见 ssl.HAS_SNI ).

从 3.6 版起弃用: keyfile and certfile 弃用代之 context 。请使用 ssl.SSLContext.load_cert_chain() 代替,或让 ssl.create_default_context() 为您选择系统的受信任 CA 证书。

3.9 版改变: timeout 参数被设为 0,它将引发 ValueError 以阻止非阻塞套接字的创建。 encoding 参数被添加,且默认从 Latin-1 改为 UTF-8 遵循 RFC 2640 .

这里的样本会话使用 FTP_TLS 类:

>>> 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']
									
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 .

另请参阅

模块 netrc

Parser for the .netrc 文件格式。文件 .netrc is typically used by FTP clients to load user authentication information before prompting the user.

FTP 对象

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 对于二进制版本。

FTP 实例具有下列方法:

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.

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

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. source_address 是 2 元组 (host, port) for the socket to bind to as its source address before connecting.

引发 审计事件 ftplib.connect 采用自变量 self , host , port .

3.3 版改变: source_address 参数被添加。

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='anonymous' , passwd='' , acct='' )

登录作为给定 user passwd and acct parameters are optional and default to the empty string. If no user is specified, it defaults to 'anonymous' 。若 user is 'anonymous' ,默认 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 ( cmd )

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

引发 审计事件 ftplib.sendcmd 采用自变量 self , cmd .

FTP. voidcmd ( cmd )

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 否则。

引发 审计事件 ftplib.sendcmd 采用自变量 self , cmd .

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

以二进制传输模式检索文件。 cmd should be an appropriate RETR 命令: 'RETR filename' callback function is called for each block of data received, with a single bytes argument giving the data block. The optional blocksize 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() 方法。

FTP. 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 命令 (见 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 检索文件名列表。 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 .

FTP. set_pasv ( val )

Enable “passive” mode if val is true, otherwise disable passive mode. Passive mode is on by default.

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

以二进制传输模式存储文件。 cmd should be an appropriate STOR 命令: "STOR filename" . fp 文件对象 (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 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 transfercmd() 方法。

3.2 版改变: rest 参数被添加。

FTP. storlines ( cmd , fp , callback=None )

以行模式存储文件。 cmd should be an appropriate STOR 命令 (见 storbinary() ). Lines are read until EOF from the 文件对象 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.

FTP. 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.

若可选 rest is given, a REST command is sent to the server, passing rest 作为自变量。 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 命令, error_reply exception will be raised. If this happens, simply call transfercmd() without a rest 自变量。

FTP. ntransfercmd ( cmd , rest=None )

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() .

FTP. mlsd ( path="" , facts=[] )

以标准化格式列表目录通过使用 MLSD 命令 ( RFC 3659 )。若 path 被省略,假定当前目录。 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.

3.3 版新增。

FTP. nlst ( argument [ , ... ] )

Return a list of file names as returned by the NLST 命令。可选 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 命令。

注意

若服务器支持命令, mlsd() 提供了更好的 API。

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 retrlines() ;默认打印到 sys.stdout 。此方法返回 None .

注意

若服务器支持命令, mlsd() 提供了更好的 API。

FTP. rename ( fromname , toname )

重命名文件 fromname 在服务器到 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 or error_reply on other errors.

FTP. cwd ( pathname )

设置服务器中的当前目录。

FTP. mkd ( pathname )

在服务器中创建新的目录。

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 the SIZE command is not standardized, but is supported by many common server implementations.

FTP. quit ( )

发送 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).

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 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() 方法)。

FTP_TLS 对象

FTP_TLS 类继承自 FTP ,定义了这些额外对象:

FTP_TLS. ssl_version

要使用的 SSL 版本 (默认为 ssl.PROTOCOL_SSLv23 ).

FTP_TLS. auth ( )

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

3.4 版改变: 方法现在支持主机名校验采用 ssl.SSLContext.check_hostname and SNI (服务器名称指示) (见 ssl.HAS_SNI ).

FTP_TLS. 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.

3.3 版新增。

FTP_TLS. prot_p ( )

建立安全数据连接。

FTP_TLS. prot_c ( )

建立明文数据连接。