def cutTree(oldfilename, treenames, **kwargs):
"""Extract tree from file and save in new one."""
start_here = time.time()
# TREENAME
treename = ""
if isinstance(treenames, str): treenames = [treenames]
if len(treenames) == 1: treename = "_%s" % treenames[0]
print ">>>\n>>> extracting tree(s) from file"
N = kwargs.get('N', -1)
# CUTS
cuts = kwargs.get('cuts', "channel>0")
if isinstance(cuts, str): cuts = [cuts] * len(treenames)
if len(treenames) != len(cuts):
print ">>> Warning! len(treenames)!=len(cuts)"
# FILE OPTIONS
newfilename = kwargs.get('newfilename', False)
update = kwargs.get('update', False)
if not newfilename:
if update: newfilename = oldfilename
else:
newfilename = oldfilename.replace(".root",
"%s_string.root" % (treename))
copycontents = kwargs.get('copycontents',
False) and oldfilename != newfilename
option = 'read' if copycontents else ('update' if update else 'recreate')
option = kwargs.get('option', option)
label = kwargs.get('label', "_cut" if (oldfilename == newfilename) else "")
# FILE
oldfile = TFile(oldfilename)
if copycontents: succes = oldfile.Cp(newfilename, True)
newfile = TFile(newfilename, 'update')
# PRINT
print ">>> file in: \"%s\"" % (oldfilename)
print ">>> file out: \"%s\"" % (newfilename)
print ">>> tree label: \"%s\"" % (label)
print ">>> settings: update=%s, option=\"%s\", copycontents=%s" % (
update, option, copycontents)
for treename, cut in zip(treenames, cuts):
oldtree = oldfile.Get(treename)
newtreename = treename + label
print ">>> copying tree \"%s\" into \"%s\" with cuts" % (treename,
newtreename)
print ">>> \"%s\"" % (cut)
newtree = None
maxmessage = ""
if N > 0:
newtree = oldtree.CopyTree(cut, "", N)
maxmessage = " (max %i)" % N
else:
newtree = oldtree.CopyTree(cut)
#newtree.SetName(newtreename)
newtree.Write(newtreename, TObject.kOverwrite)
print ">>> extraction done: %i%s of %i entries copied" % (
newtree.GetEntries(), maxmessage, oldtree.GetEntries())
print ">>> writing and closing new file: %s" % (newfilename)
#newfile.Write(TObject.kOverwrite)
newfile.Close()
oldfile.Close()
print ">>> took %.2f seconds." % (time.time() - start_here)
