[roottest] Update Python version in reference notebooks in JupyROOT test

We only support Python 3 at this point. By updating the reference
notebooks to have the Python 3 kernel in the metainfo, we don't need to
do extra steps in the `nbdiff.py` script, mapping injecting the
`python3` kernel name manually.

Author: guitargeek

roottest/python/JupyROOT/importROOT.ipynb

@@ -14,21 +14,21 @@
  ],
  "metadata": {
   "kernelspec": {
-   "display_name": "Python 2",
+   "display_name": "Python 3",
    "language": "python",
-   "name": "python2"
+   "name": "python3"
   },
   "language_info": {
    "codemirror_mode": {
     "name": "ipython",
-    "version": 2
+    "version": 3
    },
    "file_extension": ".py",
    "mimetype": "text/x-python",
    "name": "python",
    "nbconvert_exporter": "python",
-   "pygments_lexer": "ipython2",
-   "version": "2.7.6"
+   "pygments_lexer": "ipython3",
+   "version": "3.11.9"
   }
  },
  "nbformat": 4,

roottest/python/JupyROOT/nbdiff.py

@@ -7,9 +7,9 @@
 
 
 # Replace the criterion according to which a line shall be skipped
-def customLineJunkFilter(line):
+def should_keep_line(line):
     # Skip the banner and empty lines
-    junkLines = [
+    skip_patterns = [
         "Info in <TUnixSystem::ACLiC",
         "Info in <TMacOSXSystem::ACLiC",
         "FAILED TO establish the default connection to the WindowServer",
@@ -18,8 +18,8 @@ def customLineJunkFilter(line):
         '     "execution_count":',
         "libclang_rt.asan-",
     ]
-    for junkLine in junkLines:
-        if junkLine in line:
+    for pattern in skip_patterns:
+        if pattern in line:
             return False
     return True
 
@@ -44,7 +44,7 @@ def removeCellMetadata(lines):
 
 def getFilteredLines(fileName):
     with open(fileName) as f:
-        filteredLines = list(filter(customLineJunkFilter, f.readlines()))
+        filteredLines = list(filter(should_keep_line, f.readlines()))
 
     # Sometimes the jupyter server adds a new line at the end of the notebook
     # and nbconvert does not.
@@ -136,10 +136,7 @@ def addEtcToEnvironment(inNBDirName):
 def getKernelName(inNBName):
     with open(inNBName) as f:
         nbj = json.load(f)
-    if nbj["metadata"]["kernelspec"]["language"] == "python":
-        return "python3"
-    else:  # we support only Python and C++
-        return "root"
+    return nbj["metadata"]["kernelspec"]["name"]
 
 
 def canReproduceNotebook(inNBName, needsCompare):

roottest/python/JupyROOT/simpleCppMagic.ipynb

@@ -90,21 +90,21 @@
  ],
  "metadata": {
   "kernelspec": {
-   "display_name": "Python 2",
+   "display_name": "Python 3",
    "language": "python",
-   "name": "python2"
+   "name": "python3"
   },
   "language_info": {
    "codemirror_mode": {
     "name": "ipython",
-    "version": 2
+    "version": 3
    },
    "file_extension": ".py",
    "mimetype": "text/x-python",
    "name": "python",
    "nbconvert_exporter": "python",
-   "pygments_lexer": "ipython2",
-   "version": "2.7.6"
+   "pygments_lexer": "ipython3",
+   "version": "3.11.9"
   }
  },
  "nbformat": 4,