Using 3rd python library: pyping

Ignition
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1

Hi, I’d like to use the following library
https://pypi.org/project/pyping/
in my Python scripts. I downloaded the library and got the following files:

where the pyping folder containes the core.py module with the core functions.
I tried copying the whole folders structure into the /user-lib/pylib ignition folder, but I cannot call any of the library functions and moreover import pyping returns an error.
So: what should I import in order to have that library work in my scripts?

(Ignition version: 7.9.8)

Thanks in advance

2

What version of Python does it use? 2.5? 2.7? 3?

3

I don’t know really. The only thing I can grasp from the library homepage is the date of the last commit: 2016. But as a general question: is the way I went right to include a 3rd party library?

4

I think you’re close: https://support.inductiveautomation.com/index.php?/Knowledgebase/Article/View/98/2/importing-and-using-3rd-party-python-libraries-in-ignition

This library looks to be in Python 3 as well as require root/administrator access to run, so it’s unlikely you’re going to be able to use it.

edit: worth a try if you can get the import working. Looks like you just need the pyping folder and not all the other stuff in the zip. The only reason I have to think it’s Python 3 is because one of the history entries mentions converting to it.

5

The other question is “why do you need to ping anything?”

6

Might be able to use something like

import os
os.system("ping " + hostname)

I haven’t done much with that personally but it may be worth some research if you need to ping something.

7

os.system does not give you any output from the command. I would do either of the following:

  1. Use Popen
from subprocess import Popen,PIPE
p = Popen("ping -n 1 www.google.com",stdout = PIPE)
output,err = p.communicate("")
print output[output.find("time")+5:output.find("TTL")-3]

Or
2. Use a module, depending on your goals

1 Like
8

Thanks to all for your kind suggestions: I will try all of them.

9

Just augmenting @Kyle_Chase’s good suggestion. You could create a script in your project script library called inetutils:

import sys
import re
from subprocess import Popen, PIPE

def ping(host, count=1, timeout=1000):
	if sys.platform == 'win32':
		count_arg = '-n'
		timeout_arg = '-w'
	else:
		count_arg = '-c'
		timeout_arg = '-W'
	
	args = map(str, [ 'ping', count_arg, count, timeout_arg, timeout, host ])
	
	p = Popen(args, stdout=PIPE, stderr=PIPE)
	output, err = p.communicate()
	
	if p.returncode == 0:  # success
		try:
			m = re.search("time=(\d+(?:\.\d+){0,1})\s*ms", output)
			time = float(m.group(1))
		except Exception, e:
			time = -1
	else:
		time = None
		
	return (time, p.returncode)

Then, in your project, you can use the something like the following:

from project.inetutils import ping

time, result = ping('google.com')
if result == 0:
	print 'Success, response time is: %.2fms' % time
else:
	print 'Failure, return code: %d' % result

The above solution will leverage the return code of the subprocess call, where 0 is a successful result. Other return codes will produce based on various failures of the call to ping such as 68 for unknown host, or 2 for response timeout. Keep in mind that this is still going to be a blocking call, so use accordingly.

Hope this helps!

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