let's say we have two functions:
def ftpConnect():
ftp = FTP('server')
ftp.login()
ftp.cwd('/path')
def getFileList():
ftpConnect()
files = ftp.nlst()
print(files)
If I call the getFileList() function it won't work because it doesn't know the ftp var.
I know that if I declare the ftp variable inside ftpConnect() function as global it will work, but I was wondering if there is a better / more elegant way of doing it.
Functions can return values. Return values are cool!
Return ftp from ftpConnect():
def ftpConnect():
ftp = FTP('server')
ftp.login()
ftp.cwd('/path')
# return the value of `ftp` to the caller
return ftp
def getFileList():
# assign the return value of `ftpConnect` to a new local variable
ftp = ftpConnect()
files = ftp.nlst()
print(ftp.nlst())
You may also want to look in to object-oriented programming techniques; define a class that handles all your FTP-related operations, and store the FTP server connection as an attribute of the instance.
Return ftp from ftpConnect() and assign the return value to a variable named ftp:
def ftpConnect():
ftp = FTP('server')
ftp.login()
ftp.cwd('/path')
return ftp #return ftp from here
def getFileList():
ftp = ftpConnect() # assign the returned value from the
# function call to a variable
files = ftp.nlst()
print(ftp.nlst())
In my opinion, the most elegant solution would be to make a FTP-class, which would have the ftp-variable as a private attribute.
class FTPConnection(object):
def __init__(self, server):
self._ftp = FTP(server)
def connect(self):
self._ftp.login()
self._ftp.cwd('/path')
def getFileList():
files = self._ftp.nlst()
print(files)
ftp = FTPConnection('server')
ftp.connect()
ftp.getFileList()
