Develop Reference

Add GPS to Your Raspberry Pi Project with Google Maps Pubnub

(I'm following this tutorial : https://www.pubnub.com/blog/raspberry-pi-gps-lte-google-maps-api/ and I use a Raspberry pi 4 model B connected trough wifi )
I carefully followed all steps carefully untill I tried to run the modified gps_simpletest.py file. When I try to run it I get the following error:
Traceback (most recent call last):
File "/usr/lib/python3/dist-packages/serial/serialposix.py", line 323, in _rec onfigure_port
orig_attr = termios.tcgetattr(self.fd)
termios.error: (5, 'Input/output error')
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "gps_simpletest.py", line 21, in <module>
uart = serial.Serial("/dev/ttyS0", baudrate=9600, timeout=10)
File "/usr/lib/python3/dist-packages/serial/serialutil.py", line 240, in __ini t__
self.open()
File "/usr/lib/python3/dist-packages/serial/serialposix.py", line 272, in open
self._reconfigure_port(force_update=True)
File "/usr/lib/python3/dist-packages/serial/serialposix.py", line 326, in _rec onfigure_port
raise SerialException("Could not configure port: {}".format(msg))
serial.seria
I'm pretty sure I installed all modules, libraries, ....
Any help would be much appreciated!Thanks in advance

Most recent SFTP python package and best practices

I've been looking for SFTP python packages, ftpretty works fine for me:
https://pypi.org/project/ftpretty/
but I want to use a more secure protocol.
PySftp is obviously a bit outdated (Edit: it seems that pysftp is still frequently used, about the error please see below):
https://bitbucket.org/dundeemt/pysftp/src/master/
And throws me several errors on Win10, PyCharm, Python3.6:
C:\Users\bobin\PycharmProjects\classtest\venv\lib\site-packages\pysftp\__init__.py:61: UserWarning: Failed to load HostKeys from C:\Users\bobin\.ssh\known_hosts. You will need to explicitly load HostKeys (cnopts.hostkeys.load(filename)) or disableHostKey checking (cnopts.hostkeys = None).
warnings.warn(wmsg, UserWarning)
Traceback (most recent call last):
File "C:/Users/bobin/PycharmProjects/classtest/pysftptest.py", line 7, in <module>
with pysftp.Connection(host=myHostname, username=myUsername, password=myPassword) as sftp:
File "C:\Users\bobin\PycharmProjects\classtest\venv\lib\site-packages\pysftp\__init__.py", line 132, in __init__
self._tconnect['hostkey'] = self._cnopts.get_hostkey(host)
File "C:\Users\bobin\PycharmProjects\classtest\venv\lib\site-packages\pysftp\__init__.py", line 71, in get_hostkey
raise SSHException("No hostkey for host %s found." % host)
paramiko.ssh_exception.SSHException: No hostkey for host s233.goserver.host found.
Exception ignored in: <bound method Connection.__del__ of <pysftp.Connection object at 0x00000235B0695048>>
Traceback (most recent call last):
File "C:\Users\bobin\PycharmProjects\classtest\venv\lib\site-packages\pysftp\__init__.py", line 1013, in __del__
self.close()
File "C:\Users\bobin\PycharmProjects\classtest\venv\lib\site-packages\pysftp\__init__.py", line 784, in close
if self._sftp_live:
AttributeError: 'Connection' object has no attribute '_sftp_live'
Process finished with exit code 1
This thread seemed relevant to me but it's already 12years old:
SFTP in Python? (platform independent)
And the paramiko package is also throwing me errors:
Traceback (most recent call last):
File "C:\Users\bobin\PycharmProjects\classtest\venv\lib\site-packages\paramiko\sftp_client.py", line 130, in __init__
server_version = self._send_version()
File "C:\Users\bobin\PycharmProjects\classtest\venv\lib\site-packages\paramiko\sftp.py", line 134, in _send_version
t, data = self._read_packet()
File "C:\Users\bobin\PycharmProjects\classtest\venv\lib\site-packages\paramiko\sftp.py", line 201, in _read_packet
x = self._read_all(4)
File "C:\Users\bobin\PycharmProjects\classtest\venv\lib\site-packages\paramiko\sftp.py", line 188, in _read_all
raise EOFError()
EOFError
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "C:/Users/bobin/PycharmProjects/classtest/paramikotest.py", line 12, in <module>
sftp = paramiko.SFTPClient.from_transport(transport)
File "C:\Users\bobin\PycharmProjects\classtest\venv\lib\site-packages\paramiko\sftp_client.py", line 170, in from_transport
return cls(chan)
File "C:\Users\bobin\PycharmProjects\classtest\venv\lib\site-packages\paramiko\sftp_client.py", line 132, in __init__
raise SSHException("EOF during negotiation")
paramiko.ssh_exception.SSHException: EOF during negotiation
Process finished with exit code 1
I have come so far to understand that I probably need a keyfile that I can find out by first connecting to my webspace using e.g. filezilla:
How To Extract SFTP SSH Key From Key Cache in FileZilla FTP Client
My question is: how do I establish an SFTP connection to my host, which is webgo: https://www.webgo.de/hilfe/content/76/52/de/was-ist-sftp.html
EDIT: providing no host_key as follows:
import pysftp
cnopts = pysftp.CnOpts()
cnopts.hostkeys = None
myHostname = "host"
myUsername = "user"
myPassword = "pass"
with pysftp.Connection(host=myHostname, username=myUsername, password=myPassword, cnopts=cnopts, port=22) as sftp:
print("Connection succesfully stablished ... ")
sftp.put('C:\TEMP\Capture.PNG', preserve_mtime=True)
still throws me an error for providing no host_keys:
C:\Users\bobin\PycharmProjects\classtest\venv\lib\site-packages\pysftp\__init__.py:61: UserWarning: Failed to load HostKeys from C:\Users\bobin\.ssh\known_hosts. You will need to explicitly load HostKeys (cnopts.hostkeys.load(filename)) or disableHostKey checking (cnopts.hostkeys = None).
warnings.warn(wmsg, UserWarning)
EDIT2: tried prettyftp but my provider is refusing the connection:
Traceback (most recent call last):
File "C:/Users/bobin/PycharmProjects/classtest/testftp.py", line 15, in <module>
f.put('C:\TEMP\Capture.PNG', 'Capture230.PNG')
File "C:\Users\bobin\PycharmProjects\classtest\venv\lib\site-packages\ftpretty.py", line 119, in put
self.conn.storbinary('STOR %s' % remote_file, local_file)
File "C:\Users\bobin\AppData\Local\Programs\Python\Python36\lib\ftplib.py", line 513, in storbinary
return self.voidresp()
File "C:\Users\bobin\AppData\Local\Programs\Python\Python36\lib\ftplib.py", line 249, in voidresp
resp = self.getresp()
File "C:\Users\bobin\AppData\Local\Programs\Python\Python36\lib\ftplib.py", line 242, in getresp
raise error_temp(resp)
ftplib.error_temp: 425 Unable to build data connection: Operation not permitted
Used following code snippet, setting secure=False worked again:
from ftpretty import ftpretty
# Minimal
f = ftpretty('host','user','pass', port=21, secure=True)
f.put('C:\TEMP\Capture.PNG', 'Capture230.PNG')
f.close()

For the first error, it seems like a bug in pysftp.
You can have a look at the Connection class here on line 76, and the attribute _sftp_live is defined on line 134, so this is definitely an error occurring at runtime without being validated correctly. I have also been able to find this related error, which likely explains the cause of this issue; the solution is also mentioned in the error if you want to explicitly fix it.
I would still consider using ftpretty. It does use TLS for security and a pretty safe wrapper, you can simply enable it by setting the secure parameter to True (secure=True) - which by default is set as False.

Python 2.7 and Pyo, Server must be booted before creating any audio project

I am using Pyo (http://ajaxsoundstudio.com/software/pyo/) in Python 2.7.14 and I an trying to play an audio file with this code
from pyo import *
s = Server()
s.boot()
s.start()
sf = SfPlayer("C:\Users\name\Downloads\audio.mp3", speed=1, loop=True).out()
but I get this message:
Traceback (most recent call last):
File "C:\Python27\pyotest.py", line 5, in <module>
sf = SfPlayer("C:\Users\name\Downloads\audio.mp3", speed=1, loop=True).out()
File "C:\Python27\lib\site-packages\pyolib\players.py", line 98, in __init__
PyoObject.__init__(self, mul, add)
File "C:\Python27\lib\site-packages\pyolib\_core.py", line 967, in __init__
PyoObjectBase.__init__(self)
File "C:\Python27\lib\site-packages\pyolib\_core.py", line 809, in __init__
raise PyoServerStateException("The Server must be booted before "
PyoServerStateException: The Server must be booted before creating any audio object.

I had the same error once (on Windows). Started the E-Pyo Editor that comes with installing Pyo. After that it worked fine.
If that doesn't help you might want to set the server options and the output device manually.
Get the ID of the desired output device with
pa_list_devices()
If you found your ID you can set it with this command (change the 0 to your device ID) and then boot the server:
s.setOutputDevice(0)
s.boot()

Getting an EOFError when getting large files with Paramiko

I'm trying to write a quick python script to grab some logs with sftp. My first inclination was to use Pysftp, since it seemed like it made it very simple. It worked great, until it got to a larger file. I got an error while getting any file over about 13 MB. I then decided to try writing what I needed directly in Paramiko, rather than relying on the extra layer of Pysftp. After figuring out how to do that, I ended up getting the exact same error. Here's the Paramiko code, as well as the trace from the error I get. Does anyone have any idea why this would have an issue pulling any largish files? Thanks.
# Create tranport and connect
transport = paramiko.Transport((host, 22))
transport.connect(username=username, password=password)
sftp = paramiko.SFTPClient.from_transport(transport)
# List of the log files in c:
files = sftp.listdir('c:/logs')
# Now pull them, logging as you go
for f in files:
if f[0].lower() == 't' or f[:3].lower() == 'std':
logger.info('Pulling {0}'.format(f))
sftp.get('c:/logs/{0}'.format(f), output_dir +'/{0}'.format(f))
# Close the connection
sftp.close()
transport.close()
And here's the error:
No handlers could be found for logger "paramiko.transport"
Traceback (most recent call last):
File "pull_logs.py", line 420, in <module> main()
File "pull_logs.py", line 410, in main
pull_logs(username, host, password, location)
File "pull_logs.py", line 142, in pull_logs
sftp.get('c:/logs/{0}'.format(f), output_dir +'/{0}'.format(f))
File "/Users/me/my_site/site_packages/paramiko/sftp_client.py", line 676, in get
size = self.getfo(remotepath, fl, callback)
File "/Users/me/my_site/site_packages/paramiko/sftp_client.py", line 645, in getfo
data = fr.read(32768)
File "/Users/me/my_site/site_packages/paramiko/file.py", line 153, in read
new_data = self._read(read_size)
File "/Users/me/my_site/site_packages/paramiko/sftp_file.py", line 152, in _read
data = self._read_prefetch(size)
File "/Users/me/my_site/site_packages/paramiko/sftp_file.py", line 132, in _read_prefetch
self.sftp._read_response()
File "/Users/me/my_site/site_packages/paramiko/sftp_client.py", line 721, in _read_response
raise SSHException('Server connection dropped: %s' % (str(e),))
paramiko.SSHException: Server connection dropped:

Why cannot call method in org.freedesktop.NetworkManager with dbus in Python?

I tried the code below in interactive python shell and got the follow error in line 3 of code, using D-Feet I see that path and interface exists in bus, and with the command dbus-send I able to get the devices, see in end of this message. Why not work with this code in python? PS: I using ubuntu 12.04, tried too in ubuntu 11, same problem.
Code:
import dbus
bus = dbus.SessionBus()
obj = bus.get_object('org.freedesktop.NetworkManager', '/org/freedesktop/NetworkManager')
t = dbus.Interface(obj, "org.freedesktop.NetworkManager")
t.GetDevices()
Output error entering line 3 of code:
Traceback (most recent call last):
File "<input>", line 1, in <module>
File "/usr/lib/pymodules/python2.7/dbus/bus.py", line 244, in get_object
follow_name_owner_changes=follow_name_owner_changes)
File "/usr/lib/pymodules/python2.7/dbus/proxies.py", line 241, in __init__
self._named_service = conn.activate_name_owner(bus_name)
File "/usr/lib/pymodules/python2.7/dbus/bus.py", line 183, in activate_name_owner
self.start_service_by_name(bus_name)
File "/usr/lib/pymodules/python2.7/dbus/bus.py", line 281, in start_service_by_name
'su', (bus_name, flags)))
File "/usr/lib/pymodules/python2.7/dbus/connection.py", line 630, in call_blocking
message, timeout)
DBusException: org.freedesktop.DBus.Error.ServiceUnknown: The name org.freedesktop.NetworkManager was not provided
by any .service files
Shell command that work:
dbus-send --system --print-reply --reply-timeout=2000 --type=method_call --dest=org.freedesktop.NetworkManager /org/freedesktop/NetworkManager org.freedesktop.NetworkManager.GetDevices
Output:
method return sender=:1.2 -> dest=:1.69 reply_serial=2
array [
object path "/org/freedesktop/NetworkManager/Devices/0"
]
This is just a example, I wish to know why don't work, If I change line 3 to (note the DBus name in first parameter):
obj = bus.get_object('org.freedesktop.DBus', '/org/freedesktop/NetworkManager')
the error don't occur, but in this interface the method GetDevices doesn't exists.

In your command line example you're asking for the system bus:
dbus-send --system ...
In your Python code, you're asking for the session bus:
bus = dbus.SessionBus()
If you try the request over the system bus, I think you'll find that it works:
>>> import dbus
>>> bus = dbus.SystemBus()
>>> obj = bus.get_object('org.freedesktop.NetworkManager', '/org/freedesktop/NetworkManager')
>>> t = dbus.Interface(obj, "org.freedesktop.NetworkManager")
>>> t.GetDevices()
dbus.Array([dbus.ObjectPath('/org/freedesktop/NetworkManager/Devices/0'), dbus.ObjectPath('/org/freedesktop/NetworkManager/Devices/1')], signature=dbus.Signature('o'))
>>>