[DF] Use different filenames in python and C tutorials

Lest they step on each other's feet when running all tutorials
e.g. via ctest.

tutorials/dataframe/df003_profiles.py

@@ -25,7 +25,7 @@ def fill_tree(treeName, fileName):
 
 
 # We prepare an input tree to run on
-fileName = "df003_profiles.root"
+fileName = "df003_profiles_py.root"
 treeName = "myTree"
 fill_tree(treeName, fileName)
 

tutorials/dataframe/df008_createDataSetFromScratch.py

@@ -17,5 +17,5 @@ ROOT.gRandom.SetSeed(1)
 tdf_1 = tdf.Define("rnd", "gRandom->Gaus()")
 
 # And we write out the dataset on disk
-tdf_1.Snapshot("randomNumbers", "df008_createDataSetFromScratch.root")
+tdf_1.Snapshot("randomNumbers", "df008_createDataSetFromScratch_py.root")
 

tutorials/dataframe/df017_vecOpsHEP.py

@@ -11,7 +11,7 @@
 import ROOT
 from math import sqrt
 
-filename = ROOT.gROOT.GetTutorialDir().Data() + "/dataframe/df017_vecOpsHEP.root"
+filename = ROOT.gROOT.GetTutorialDir().Data() + "/dataframe/df017_vecOpsHEP_py.root"
 treename = "myDataset"
 RDF = ROOT.ROOT.RDataFrame