ImportError: cannot import name WINFUNCTYPE

Ignition
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1

Hi all,
I am new to Ignition Perspective and I am using a 8.1.1 version. I am trying to extract information from a windows file and convert it into the ASCII but when I am running the code I am repeatedly having this error. Please give your inputs for below code:

from ctypes import POINTER, WINFUNCTYPE, c_char_p, c_void_p, c_int, c_ulong, c_char_p
from ctypes.wintypes import BOOL, DWORD, BYTE, INT, LPCWSTR, UINT, LONG, ULONG, LPCSTR, PCHAR, PWCHAR
import ctypes
from ctypes import byref
import sys
import os, glob

tcAccessDll = r"C:\Users\himanshu.choubisa\Desktop\TcAccess.dll"
rstfilename = b"C:\Users\himanshu.choubisa\Desktop\RA03534 AGAS UK 70+4min 130521B.rst"

#check newest results file :slight_smile:
#rstfilename = min(glob.iglob(‘C:\TCData\Data\*.rst’), key=os.path.getctime).encode(‘ascii’)

Load DLL into memory.

#hllDll = ctypes.WinDLL (r"c:\PenExe\TcWS\Ver6.3.4\Bin\TcAccess.dll")#

#hllDll = ctypes.cdll.LoadLibrary (r"c:\PenExe\TcWS\Ver6.3.4\Bin\TcAccess.dll")

#hllDll = ctypes.WinDLL (r"c:/PenExe/TcWS/Ver6.3.4/Bin/TcAccess.dll")

#hllDll = ctypes.WinDLL (“TcAccess.dll”)

def get_winfunc(libname, funcname, restype=None, argtypes=(), _libcache={}):
“”“Retrieve a function from a library, and set the data types.”""
from ctypes import windll

if libname not in _libcache:
    _libcache[libname] = ctypes.cdll.LoadLibrary(libname)
func = getattr(_libcache[libname], funcname)
func.argtypes = argtypes
func.restype = restype

return func

class TCAccess(object):
Init = get_winfunc(tcAccessDll, “TcAccessInit”)
LoggedIn = get_winfunc(tcAccessDll,“TcAccessLoggedOn”, BOOL)
OpenConversation = get_winfunc(tcAccessDll, “TcAccessOpenConversation”,LONG,[LPCSTR])
CloseConversation = get_winfunc(tcAccessDll, “TcAccessCloseConversation”, INT, [INT])
Set = get_winfunc(tcAccessDll, “TcAccessSet”, INT, [INT,LPCSTR,LPCSTR])
Get = get_winfunc(tcAccessDll, “TcAccessGet”, LPCSTR, [INT, LPCSTR])

print(TCAccess.Init())
print(TCAccess.LoggedIn())
topic = ‘RST’
c=(TCAccess.OpenConversation(b"RST"))
print(c)
print(TCAccess.Set(c,b"RST_FILE_NAME",rstfilename))
peakcount = int((TCAccess.Get(c,b"Rst_Num_Peaks")))
for index in range(peakcount):
(TCAccess.Set(c,b"RST_COMP_INDEX",str(index).encode(‘ascii’)))
CompName=(TCAccess.Get(c,b"CP_COMP_NAME").decode())
(TCAccess.Get(c,b"CP_PEAK_VECTOR"))
(TCAccess.Get(c,b"RST_PEAK_INDEX"))
CompArea=(TCAccess.Get(c,b"PK_AREA_PCT").decode())
CompResult=(TCAccess.Get(c,b"PK_RESULT").decode())
print ("Component " + CompName + " Peak Area %: " + CompArea + " Peak Concentration: " + CompResult)

2

Jython’s ctypes implementation is incomplete.

Generally, you should not expect to be able to load DLLs or C libraries with Jython nor do Python libraries that wrap C libraries work inside Ignition.

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3

Thanks Kevin for your inputs
however, I cant work out how to have the correct implementation of ctypes.
Will you please elaborate with the correct code?
Thanks in advance

4

There is no correct code. You cannot access .DLL files from jython or java. You would need to write another C layer with JNA to access the DLL for you, and wrap it in a java class. Then import that from jython.

It would probably be simpler to write a webservice in CPython to use the existing code, and make requests from Ignition to the webservice.

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