newbie question About O'Reilly "Python for Unix and Linux SystemAdministration" ftp Mirror question

[moonhkt]

Hi All


O'Reilly Book ISBN 978-986-6840-36-4.

python --version
Python 2.6.2 on AIX 5.3

Using this python to get files in ftp server.

I got below error. What is the error meaning and how to fix ?

ftp_mirror.py
Traceback (most recent call last):
File "/xx../shell/ftpmirror.py", line 80, in <module>
f = FTPSync(options.host, options.username, options.password,
options.remote_dir, options.local_dir, opti
ons.delete)
File "xx../shell/ftpmirror.py", line 17, in __init__
self.conn.cwd(ftp_base_dir)
File "/opt/freeware/lib/python2.6/ftplib.py", line 536, in cwd
cmd = 'CWD ' + dirname
TypeError: cannot concatenate 'str' and 'NoneType' objects

Source :

#!/usr/bin/env python

import ftplib
import os

class FTPSync(object):
def __init__(self, host, username, password, ftp_base_dir,
local_base_dir, delete=False):
self.host = host
self.username = username
self.password = password
self.ftp_base_dir = ftp_base_dir
self.local_base_dir = local_base_dir
self.delete = delete

self.conn = ftplib.FTP(host, username, password)
self.conn.cwd(ftp_base_dir)
try:
os.makedirs(local_base_dir)
except OSError:
pass
os.chdir(local_base_dir)
def get_dirs_files(self):
dir_res = []
self.conn.dir('.', dir_res.append)
files = [f.split(None, 8)[-1] for f in dir_res if
f.startswith('-')]
dirs = [f.split(None, 8)[-1] for f in dir_res if
f.startswith('d')]
return (files, dirs)
def walk(self, next_dir):
print "Walking to", next_dir
self.conn.cwd(next_dir)
try:
os.mkdir(next_dir)
except OSError:
pass
os.chdir(next_dir)

ftp_curr_dir = self.conn.pwd()
local_curr_dir = os.getcwd()

files, dirs = self.get_dirs_files()
print "FILES:", files
print "DIRS:", dirs
for f in files:
print next_dir, ':', f
outf = open(f, 'wb')
try:
self.conn.retrbinary('RETR %s' % f, outf.write)
finally:
outf.close()
if self.delete:
print "Deleting", f
self.conn.delete(f)
for d in dirs:
os.chdir(local_curr_dir)
self.conn.cwd(ftp_curr_dir)
self.walk(d)

def run(self):
self.walk('.')


if __name__ == '__main__':
from optparse import OptionParser
parser = OptionParser()
parser.add_option("-o", "--host", dest="host",
action='store', help="FTP host")
parser.add_option("-u", "--username", dest="username",
action='store', help="FTP username")
parser.add_option("-p", "--password", dest="password",
action='store', help="FTP password")
parser.add_option("-r", "--remote_dir", dest="remote_dir",
action='store', help="FTP remote starting directory")
parser.add_option("-l", "--local_dir", dest="local_dir",
action='store', help="Local starting directory")
parser.add_option("-d", "--delete", dest="delete", default=False,
action='store_true', help="use regex parser")

(options, args) = parser.parse_args()
f = FTPSync(options.host, options.username, options.password,
options.remote_dir, options.local_dir, options.delete)
f.run()

 

[Joel Goldstick]

Hi All


O'Reilly Book ISBN 978-986-6840-36-4.

python --version
Python 2.6.2 on AIX 5.3

Using this python to get files in ftp server.

I got below error. What is the error meaning and how to fix ?

ftp_mirror.py
Traceback (most recent call last):
File "/xx../shell/ftpmirror.py", line 80, in <module>
f = FTPSync(options.host, options.username, options.password,
options.remote_dir, options.local_dir, opti
ons.delete)
File "xx../shell/ftpmirror.py", line 17, in __init__
self.conn.cwd(ftp_base_dir)
File "/opt/freeware/lib/python2.6/ftplib.py", line 536, in cwd
cmd = 'CWD ' + dirname
TypeError: cannot concatenate 'str' and 'NoneType' objects

Source :

#!/usr/bin/env python

import ftplib
import os

class FTPSync(object):
def __init__(self, host, username, password, ftp_base_dir,
local_base_dir, delete=False):
self.host = host
self.username = username
self.password = password
self.ftp_base_dir = ftp_base_dir
self.local_base_dir = local_base_dir
self.delete = delete

self.conn = ftplib.FTP(host, username, password)
self.conn.cwd(ftp_base_dir)
try:
os.makedirs(local_base_dir)
except OSError:
pass
os.chdir(local_base_dir)
def get_dirs_files(self):
dir_res = []
self.conn.dir('.', dir_res.append)
files = [f.split(None, 8)[-1] for f in dir_res if
f.startswith('-')]
dirs = [f.split(None, 8)[-1] for f in dir_res if
f.startswith('d')]
return (files, dirs)
def walk(self, next_dir):
print "Walking to", next_dir
self.conn.cwd(next_dir)
try:
os.mkdir(next_dir)
except OSError:
pass
os.chdir(next_dir)

ftp_curr_dir = self.conn.pwd()
local_curr_dir = os.getcwd()

files, dirs = self.get_dirs_files()
print "FILES:", files
print "DIRS:", dirs
for f in files:
print next_dir, ':', f
outf = open(f, 'wb')
try:
self.conn.retrbinary('RETR %s' % f, outf.write)
finally:
outf.close()
if self.delete:
print "Deleting", f
self.conn.delete(f)
for d in dirs:
os.chdir(local_curr_dir)
self.conn.cwd(ftp_curr_dir)
self.walk(d)

def run(self):
self.walk('.')


if __name__ == '__main__':
from optparse import OptionParser
parser = OptionParser()
parser.add_option("-o", "--host", dest="host",
action='store', help="FTP host")
parser.add_option("-u", "--username", dest="username",
action='store', help="FTP username")
parser.add_option("-p", "--password", dest="password",
action='store', help="FTP password")
parser.add_option("-r", "--remote_dir", dest="remote_dir",
action='store', help="FTP remote starting directory")
parser.add_option("-l", "--local_dir", dest="local_dir",
action='store', help="Local starting directory")
parser.add_option("-d", "--delete", dest="delete", default=False,
action='store_true', help="use regex parser")

(options, args) = parser.parse_args()

comment the next line , then print the parameters and see what they
are. That should get you started.

#f = FTPSync(options.host, options.username, options.password,
# options.remote_dir, options.local_dir, options.delete)

f = print(options.host, options.username, options.password,
options.remote_dir, options.local_dir, options.delete)

 

[Chris Angelico]

Hi All

O'Reilly Book ISBN 978-986-6840-36-4.

python --version
Python 2.6.2 on AIX 5.3

Hi! Thanks for this, good information to open with.

Using this python to get files in ftp server.

I got below error. What is the error meaning and how to fix ?

ftp_mirror.py
Traceback (most recent call last):
File "/xx../shell/ftpmirror.py", line 80, in <module>
f = FTPSync(options.host, options.username, options.password,
options.remote_dir, options.local_dir, opti
ons.delete)
File "xx../shell/ftpmirror.py", line 17, in __init__
self.conn.cwd(ftp_base_dir)
File "/opt/freeware/lib/python2.6/ftplib.py", line 536, in cwd
cmd = 'CWD ' + dirname
TypeError: cannot concatenate 'str' and 'NoneType' objects

NoneType is the type of the singleton object None. Why are you getting
None where you ought to be providing a directory name? Heavily trimmed
code follows:

def __init__(self, host, username, password, ftp_base_dir,
local_base_dir, delete=False):
self.conn.cwd(ftp_base_dir)
parser.add_option("-r", "--remote_dir", dest="remote_dir",
action='store', help="FTP remote starting directory")
f = FTPSync(options.host, options.username, options.password,
options.remote_dir, options.local_dir, options.delete)

If you don't pass -r/--remote_dir to your script, then (presumably - I
haven't actually used optparse so this is glarked from context)
options.remote_dir is being set to, or left at, None. A quick look at
the docs suggests that one solution is to add a default value to the
options:

http://docs.python.org/library/optparse.html#default-values

Alternatively, treat the options as mandatory, and provide them on the
command line.

Side point: When you go to the docs page there, you may notice that
optparse is deprecated in favour of argparse. May as well continue the
tutorial with what they recommend, but it's probably worth having a
look at argparse eventually.

Hope that helps!

Chris Angelico