--- a/py_ext/py_ext.py	Fri Dec 16 13:41:03 2022 +0100
+++ b/py_ext/py_ext.py	Fri Dec 16 13:43:38 2022 +0100
@@ -30,6 +30,98 @@
 from py_ext.PythonFileCTNMixin import PythonFileCTNMixin
 import util.paths as paths
 
+pyext_python_lib_code = """
+
+import csv
+from collections import OrderedDict
+
+csv_int_files = {}
+def CSVRdInt(fname, rowidx, colidx):
+    \"\"\"
+    Return value at row/column pointed by integer indexes
+    Assumes data starts at first row and first column, no headers.
+    \"\"\"
+    global csv_int_files
+    data = csv_int_files.get(fname, None)
+    if data is None:
+        data = list()
+        try:
+            csvfile = open(fname, 'rb')
+        except IOError:
+            return "#FILE_NOT_FOUND"
+        try:
+            dialect = csv.Sniffer().sniff(csvfile.read(1024))
+            csvfile.seek(0)
+            reader = csv.reader(csvfile, dialect)
+            for row in reader:
+                data.append(row)
+        except csv.Error:
+            return "#CSV_ERROR"
+        finally:
+            csvfile.close()
+        csv_int_files[fname] = data
+    
+    try:
+        row = data[rowidx]
+    except IndexError:
+        return "#ROW_NOT_FOUND"
+
+    try:
+        return row[colidx]
+    except IndexError:
+        return "#COL_NOT_FOUND"
+
+
+csv_str_files = {}
+def CSVRdStr(fname, rowname, colname):
+    \"\"\"
+    Return value at row/column pointed by a pair of names as string
+    Assumes first row is column headers and first column is row name.
+    \"\"\"
+    global csv_str_files
+    entry = csv_str_files.get(fname, None)
+    if entry is None:
+        data = dict()
+        try:
+            csvfile = open(fname, 'rb')
+        except IOError:
+            return "#FILE_NOT_FOUND"
+        try:
+            dialect = csv.Sniffer().sniff(csvfile.read(1024))
+            csvfile.seek(0)
+            reader = csv.reader(csvfile, dialect)
+            headers = dict([(name, index) for index, name in enumerate(reader.next()[1:])])
+            for row in reader:
+                data[row[0]] = row[1:]
+        except csv.Error:
+            return "#CSV_ERROR"
+        finally:
+            csvfile.close()
+        csv_str_files[fname] = (headers, data)
+    else:
+        headers, data = entry
+    
+    try:
+        row = data[rowname]
+    except KeyError:
+        return "#ROW_NOT_FOUND"
+
+    try:
+        colidx = headers[colname]
+    except KeyError:
+        return "#COL_NOT_FOUND"
+
+    try:
+        return row[colidx]
+    except IndexError:
+        return "#COL_NOT_FOUND"
+
+def pyext_csv_reload():
+    global csv_int_files, csv_str_files
+    csv_int_files.clear()
+    csv_str_files.clear()
+
+"""
 
 class PythonLibrary(POULibrary):
     def GetLibraryPath(self):
@@ -57,7 +149,13 @@
         pythonfile.write(plc_python_code)
         pythonfile.close()
 
-        return (["py_ext"], [(Gen_Pythonfile_path, IECCFLAGS)], True), ""
+        runtimefile_path = os.path.join(buildpath, "runtime_00_pyext.py")
+        runtimefile = open(runtimefile_path, 'w')
+        runtimefile.write(pyext_python_lib_code)
+        runtimefile.close()
+        return ((["py_ext"], [(Gen_Pythonfile_path, IECCFLAGS)], True), "",
+                ("runtime_00_pyext.py", open(runtimefile_path, "rb")))
+
 
 
 class PythonFile(PythonFileCTNMixin):