chore: rename ciffile to cif_path

Author: ycexiao

tests/test_pdf.py

@@ -160,8 +160,8 @@ def testGenerator(
 
     stru = PDFFitStructure()
     ciffile = datafile("ni.cif")
-    ciffile = str(ciffile)
-    stru.read(ciffile)
+    cif_path = str(ciffile)
+    stru.read(cif_path)
     for i in range(4):
         stru[i].Bisoequiv = 1
     gen.setStructure(stru)
@@ -300,8 +300,8 @@ def test_pickling(
     pc = PDFContribution("pdf")
     pc.loadData(datafile("ni-q27r100-neutron.gr"))
     ciffile = datafile("ni.cif")
-    ciffile = str(ciffile)
-    ni = loadStructure(ciffile)
+    cif_path = str(ciffile)
+    ni = loadStructure(cif_path)
     ni.Uisoequiv = 0.003
     pc.addStructure("ni", ni)
     pc.setCalculationRange(0, 10)