Merge branch 'fix/initial_condition_search' into 'master'

fixes initial condition search procedure

See merge request !109

TurTLE/DNS.py

@@ -881,12 +881,13 @@ class DNS(_code):
                         for cp in range(source_current_checkpoint+1)]
                 src_file = None
                 for check_file in source_checkpoints:
-                    f0 = h5py.File(check_file, 'r')
-                    if ('{0}'.format(opt.src_iteration)
-                       in f0[checkpoint_field + '/complex'].keys()):
-                        f0.close()
-                        src_file = check_file
-                        break
+                    if os.path.exists(check_file):
+                        f0 = h5py.File(check_file, 'r')
+                        if ('{0}'.format(opt.src_iteration)
+                           in f0[checkpoint_field + '/complex'].keys()):
+                            f0.close()
+                            src_file = check_file
+                            break
                 self.copy_complex_field(
                         src_file,
                         checkpoint_field + '/complex/{0}'.format(opt.src_iteration),