Creating an FTP client with Python
I've always thought about creating my own ftp client ever since I've started using the Internet. And now that I'm studying Python, I'm thinking about creating one as an exercises/personal project.
I'm wondering,
- What libraries do you guys suggest? Will
ftplib
suffice? Or would you suggest another library(preferably one that has good docs)? - I'm thinking about using wxPython. Is it a good idea? Should I learn it first?
- I'm coming from a Web Development开发者_如何学JAVA background. What tips/suggestions would you guys give to me?
I'd appreciate any guidance/help. Thanks in advance! :)
It sounds like you want to make a program that has a GUI. May I recommend using PyQt for that part of your application? ftplib should be fine for your FTP support, and you can find documentation right here.
Alternatively for FTP support, you can use the QFtp class from the QtNetwork module from PyQt framework. The following is an example FTP client that comes with PyQt. The images come with it.
#!/usr/bin/env python
"""PyQt4 port of the network/ftp example from Qt v4.x"""
# This is only needed for Python v2 but is harmless for Python v3.
import sip
sip.setapi('QString', 2)
from PyQt4 import QtCore, QtGui, QtNetwork
import ftp_rc
class FtpWindow(QtGui.QDialog):
def __init__(self, parent=None):
super(FtpWindow, self).__init__(parent)
self.isDirectory = {}
self.currentPath = ''
self.ftp = None
self.outFile = None
ftpServerLabel = QtGui.QLabel("Ftp &server:")
self.ftpServerLineEdit = QtGui.QLineEdit('ftp.trolltech.com')
ftpServerLabel.setBuddy(self.ftpServerLineEdit)
self.statusLabel = QtGui.QLabel("Please enter the name of an FTP server.")
self.fileList = QtGui.QTreeWidget()
self.fileList.setEnabled(False)
self.fileList.setRootIsDecorated(False)
self.fileList.setHeaderLabels(("Name", "Size", "Owner", "Group", "Time"))
self.fileList.header().setStretchLastSection(False)
self.connectButton = QtGui.QPushButton("Connect")
self.connectButton.setDefault(True)
self.cdToParentButton = QtGui.QPushButton()
self.cdToParentButton.setIcon(QtGui.QIcon(':/images/cdtoparent.png'))
self.cdToParentButton.setEnabled(False)
self.downloadButton = QtGui.QPushButton("Download")
self.downloadButton.setEnabled(False)
self.quitButton = QtGui.QPushButton("Quit")
buttonBox = QtGui.QDialogButtonBox()
buttonBox.addButton(self.downloadButton,
QtGui.QDialogButtonBox.ActionRole)
buttonBox.addButton(self.quitButton, QtGui.QDialogButtonBox.RejectRole)
self.progressDialog = QtGui.QProgressDialog(self)
self.fileList.itemActivated.connect(self.processItem)
self.fileList.currentItemChanged.connect(self.enableDownloadButton)
self.progressDialog.canceled.connect(self.cancelDownload)
self.connectButton.clicked.connect(self.connectOrDisconnect)
self.cdToParentButton.clicked.connect(self.cdToParent)
self.downloadButton.clicked.connect(self.downloadFile)
self.quitButton.clicked.connect(self.close)
topLayout = QtGui.QHBoxLayout()
topLayout.addWidget(ftpServerLabel)
topLayout.addWidget(self.ftpServerLineEdit)
topLayout.addWidget(self.cdToParentButton)
topLayout.addWidget(self.connectButton)
mainLayout = QtGui.QVBoxLayout()
mainLayout.addLayout(topLayout)
mainLayout.addWidget(self.fileList)
mainLayout.addWidget(self.statusLabel)
mainLayout.addWidget(buttonBox)
self.setLayout(mainLayout)
self.setWindowTitle("FTP")
def sizeHint(self):
return QtCore.QSize(500, 300)
def connectOrDisconnect(self):
if self.ftp:
self.ftp.abort()
self.ftp.deleteLater()
self.ftp = None
self.fileList.setEnabled(False)
self.cdToParentButton.setEnabled(False)
self.downloadButton.setEnabled(False)
self.connectButton.setEnabled(True)
self.connectButton.setText("Connect")
self.setCursor(QtCore.Qt.ArrowCursor)
return
self.setCursor(QtCore.Qt.WaitCursor)
self.ftp = QtNetwork.QFtp(self)
self.ftp.commandFinished.connect(self.ftpCommandFinished)
self.ftp.listInfo.connect(self.addToList)
self.ftp.dataTransferProgress.connect(self.updateDataTransferProgress)
self.fileList.clear()
self.currentPath = ''
self.isDirectory.clear()
url = QtCore.QUrl(self.ftpServerLineEdit.text())
if not url.isValid() or url.scheme().lower() != 'ftp':
self.ftp.connectToHost(self.ftpServerLineEdit.text(), 21)
self.ftp.login()
else:
self.ftp.connectToHost(url.host(), url.port(21))
user_name = url.userName()
if user_name:
try:
# Python v3.
user_name = bytes(user_name, encoding='latin1')
except:
# Python v2.
pass
self.ftp.login(QtCore.QUrl.fromPercentEncoding(user_name), url.password())
else:
self.ftp.login()
if url.path():
self.ftp.cd(url.path())
self.fileList.setEnabled(True)
self.connectButton.setEnabled(False)
self.connectButton.setText("Disconnect")
self.statusLabel.setText("Connecting to FTP server %s..." % self.ftpServerLineEdit.text())
def downloadFile(self):
fileName = self.fileList.currentItem().text(0)
if QtCore.QFile.exists(fileName):
QtGui.QMessageBox.information(self, "FTP",
"There already exists a file called %s in the current "
"directory." % fileName)
return
self.outFile = QtCore.QFile(fileName)
if not self.outFile.open(QtCore.QIODevice.WriteOnly):
QtGui.QMessageBox.information(self, "FTP",
"Unable to save the file %s: %s." % (fileName, self.outFile.errorString()))
self.outFile = None
return
self.ftp.get(self.fileList.currentItem().text(0), self.outFile)
self.progressDialog.setLabelText("Downloading %s..." % fileName)
self.downloadButton.setEnabled(False)
self.progressDialog.exec_()
def cancelDownload(self):
self.ftp.abort()
def ftpCommandFinished(self, _, error):
self.setCursor(QtCore.Qt.ArrowCursor)
if self.ftp.currentCommand() == QtNetwork.QFtp.ConnectToHost:
if error:
QtGui.QMessageBox.information(self, "FTP",
"Unable to connect to the FTP server at %s. Please "
"check that the host name is correct." % self.ftpServerLineEdit.text())
self.connectOrDisconnect()
return
self.statusLabel.setText("Logged onto %s." % self.ftpServerLineEdit.text())
self.fileList.setFocus()
self.downloadButton.setDefault(True)
self.connectButton.setEnabled(True)
return
if self.ftp.currentCommand() == QtNetwork.QFtp.Login:
self.ftp.list()
if self.ftp.currentCommand() == QtNetwork.QFtp.Get:
if error:
self.statusLabel.setText("Canceled download of %s." % self.outFile.fileName())
self.outFile.close()
self.outFile.remove()
else:
self.statusLabel.setText("Downloaded %s to current directory." % self.outFile.fileName())
self.outFile.close()
self.outFile = None
self.enableDownloadButton()
self.progressDialog.hide()
elif self.ftp.currentCommand() == QtNetwork.QFtp.List:
if not self.isDirectory:
self.fileList.addTopLevelItem(QtGui.QTreeWidgetItem(["<empty>"]))
self.fileList.setEnabled(False)
def addToList(self, urlInfo):
item = QtGui.QTreeWidgetItem()
item.setText(0, urlInfo.name())
item.setText(1, str(urlInfo.size()))
item.setText(2, urlInfo.owner())
item.setText(3, urlInfo.group())
item.setText(4, urlInfo.lastModified().toString('MMM dd yyyy'))
if urlInfo.isDir():
icon = QtGui.QIcon(':/images/dir.png')
else:
icon = QtGui.QIcon(':/images/file.png')
item.setIcon(0, icon)
self.isDirectory[urlInfo.name()] = urlInfo.isDir()
self.fileList.addTopLevelItem(item)
if not self.fileList.currentItem():
self.fileList.setCurrentItem(self.fileList.topLevelItem(0))
self.fileList.setEnabled(True)
def processItem(self, item):
name = item.text(0)
if self.isDirectory.get(name):
self.fileList.clear()
self.isDirectory.clear()
self.currentPath += '/' + name
self.ftp.cd(name)
self.ftp.list()
self.cdToParentButton.setEnabled(True)
self.setCursor(QtCore.Qt.WaitCursor)
def cdToParent(self):
self.setCursor(QtCore.Qt.WaitCursor)
self.fileList.clear()
self.isDirectory.clear()
dirs = self.currentPath.split('/')
if len(dirs) > 1:
self.currentPath = ''
self.cdToParentButton.setEnabled(False)
self.ftp.cd('/')
else:
self.currentPath = '/'.join(dirs[:-1])
self.ftp.cd(self.currentPath)
self.ftp.list()
def updateDataTransferProgress(self, readBytes, totalBytes):
self.progressDialog.setMaximum(totalBytes)
self.progressDialog.setValue(readBytes)
def enableDownloadButton(self):
current = self.fileList.currentItem()
if current:
currentFile = current.text(0)
self.downloadButton.setEnabled(not self.isDirectory.get(currentFile))
else:
self.downloadButton.setEnabled(False)
if __name__ == '__main__':
import sys
app = QtGui.QApplication(sys.argv)
ftpWin = FtpWindow()
ftpWin.show()
sys.exit(ftpWin.exec_())
Python's standard library is just a great place to start: http://docs.python.org/library/ftplib.html
Note: And if for some reason you want to write your own client, you can simple read the source, which is a good training exercise in itself ...
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