[HDF5Scan] Add case where the given path does not exists yet.

tomoscan/esrf/hdf5scan.py

@@ -112,7 +112,10 @@ class HDF5TomoScan(TomoScanBase):
             index = None
         # if the user give the master file instead of the scan dir...
         if scan is not None:
-            if os.path.isfile(scan):
+            if not os.path.exists(scan) and '.' in os.path.split(scan)[-1]:
+                self.master_file = scan
+                scan = os.path.dirname(scan)
+            if os.path.isfile(scan) or ():
                 self.master_file = scan
                 scan = os.path.dirname(scan)
             else: