add PdfFit class __init__ docstring and tests

Author: Tieqiong

src/diffpy/pdffit2/pdffit.py

@@ -104,7 +104,6 @@ def _convertCallable(var):
 
 
 class PdfFit(object):
-    """Create PdfFit object."""
 
     # constants and enumerators from pdffit.h:
     # selection of all atoms
@@ -1253,6 +1252,22 @@ def rcut():
     # End refinable variables.
 
     def __init__(self, intro=True):
+        """Initialize the Pdffit class, create a new PdfFit object.
+
+        Parameters
+        ----------
+        intro : bool, optional
+            If True, display an introduction message. Default is True.
+
+        Attributes
+        ----------
+        stru_files : list
+            A list to store structure files.
+        data_files : list
+            A list to store data files.
+        _handle : PyCapsule
+            A python capsules to retrieve the printer to PdfFit object.
+        """
 
         self.stru_files = []
         self.data_files = []

tests/test_pdffit.py

@@ -702,56 +702,69 @@ def test_occ(self):
             self.assertEqual(1, pf.getvar(pf.occ(i)))
         return
 
+    #   def test_pscale(self):
+    #       """check PdfFit.pscale()
+    #       """
+    #       return
+    #
+    #   def test_pscale(self):
+    #       """check PdfFit.pscale()
+    #       """
+    #       return
+    #
+    #   def test_sratio(self):
+    #       """check PdfFit.sratio()
+    #       """
+    #       return
+    #
+    #   def test_delta1(self):
+    #       """check PdfFit.delta1()
+    #       """
+    #       return
+    #
+    #   def test_delta2(self):
+    #       """check PdfFit.delta2()
+    #       """
+    #       return
+    #
+    #   def test_dscale(self):
+    #       """check PdfFit.dscale()
+    #       """
+    #       return
+    #
+    #   def test_qdamp(self):
+    #       """check PdfFit.qdamp()
+    #       """
+    #       return
+    #
+    #   def test_qbroad(self):
+    #       """check PdfFit.qbroad()
+    #       """
+    #       return
+    #
+    #   def test_rcut(self):
+    #       """check PdfFit.rcut()
+    #       """
+    #       return
+    #
+
+    def test___init__(self):
+        """Check PdfFit.__init__()"""
+        P = PdfFit()
+        self.assertEqual([], P.stru_files)
+        self.assertEqual([], P.data_files)
+
+        output_true = self.capture_output(PdfFit, intro=True).strip()
+        output_false = self.capture_output(PdfFit, intro=False).strip()
+
+        import diffpy.pdffit2.pdffit as pdffit
+
+        self.assertEqual(len(output_true), len(pdffit.__intro_message__.strip()))
+        self.assertEqual(len(output_false), 0)
+
+        return
+
 
-#   def test_pscale(self):
-#       """check PdfFit.pscale()
-#       """
-#       return
-#
-#   def test_pscale(self):
-#       """check PdfFit.pscale()
-#       """
-#       return
-#
-#   def test_sratio(self):
-#       """check PdfFit.sratio()
-#       """
-#       return
-#
-#   def test_delta1(self):
-#       """check PdfFit.delta1()
-#       """
-#       return
-#
-#   def test_delta2(self):
-#       """check PdfFit.delta2()
-#       """
-#       return
-#
-#   def test_dscale(self):
-#       """check PdfFit.dscale()
-#       """
-#       return
-#
-#   def test_qdamp(self):
-#       """check PdfFit.qdamp()
-#       """
-#       return
-#
-#   def test_qbroad(self):
-#       """check PdfFit.qbroad()
-#       """
-#       return
-#
-#   def test_rcut(self):
-#       """check PdfFit.rcut()
-#       """
-#       return
-#
-#   def test___init__(self):
-#       """check PdfFit.__init__()
-#       """
-#       return
 #
 #   def test__PdfFit__getRef(self):
 #       """check PdfFit._PdfFit__getRef()