Add loadCrystal convenience function.

Create Crystal object from a path to CIF file.
This closes #8.

Author: pavoljuhas

pyobjcryst/__init__.py

@@ -71,3 +71,19 @@
 import pyobjcryst.spacegroup
 import pyobjcryst.unitcell
 import pyobjcryst.zscatterer
+
+
+def loadCrystal(filename):
+    """Load pyobjcryst Crystal object from a CIF file.
+
+    filename -- CIF file to be loaded
+
+    Return a new Crystal object.
+
+    See pyobjcryst.crystal.CreateCrystalFromCIF for additional
+    options for constructing Crystal object from CIF data.
+    """
+    from pyobjcryst.crystal import CreateCrystalFromCIF
+    with open(filename) as fp:
+        rv = CreateCrystalFromCIF(fp)
+    return rv

pyobjcryst/tests/pyobjcrysttestutils.py

@@ -211,7 +211,7 @@ def datafile(filename):
 
 
 def loadcifdata(filename):
-    from pyobjcryst.crystal import CreateCrystalFromCIF
+    from pyobjcryst import loadCrystal
     fullpath = datafile(filename)
-    crst = CreateCrystalFromCIF(open(fullpath))
+    crst = loadCrystal(fullpath)
     return crst