fix(docs): fix import on linux machine

butterfly/__init__.py

@@ -1,16 +1,18 @@
 import re
 import os
+import warnings
+
 
 def set_config(_ofrunners):
     """set config for butterfly run manager."""
     BASEFOLDERS = {
         'ESI': r'C:\Program Files (x86)',
         'blueCFD': r'C:\Program Files'
     }
-    
+
     if not _ofrunners:
         raise ImportError('Set your installation flavor in confing.yml.')
-    
+
     # look up for folders
     for of_runner in _ofrunners:
         try:
@@ -19,6 +21,8 @@ def set_config(_ofrunners):
             # invalid installation option
             pass
         else:
+            if not os.path.isdir(base_folder):
+                continue
             for f in os.listdir(base_folder):
                 of_folder = os.path.join(base_folder, f)
                 if not os.path.isdir(of_folder):
@@ -27,12 +31,17 @@ def set_config(_ofrunners):
                     # in case of two installation finds the older one but for now
                     # it is fine.
                     return {'runner': of_runner, 'of_folder': of_folder}
-
-    raise ImportError('Set your installation flavor in confing.yml.')
+
+    warnings.warn(
+        'Failed to find the OpenFOAM installation.'
+        ' Set your installation flavor in confing.yml.'
+    )
+
 
 os.chdir(os.path.dirname(__file__))
 with open('config.yml') as inst:
     _ofrunners = re.findall(r'\s- (.*)', inst.read(),re.MULTILINE )
 
 config = set_config(_ofrunners)
-print('OpenFOAM installation: {}'.format(config['runner']))
+if config:
+    print('OpenFOAM installation: {}'.format(config['runner']))

butterfly/case.py

@@ -50,7 +50,7 @@
 
 import butterfly
 
-if butterfly.config['runner'] == 'blueCFD':
+if butterfly.config and butterfly.config['runner'] == 'blueCFD':
     from .runmanager_bluecfd import RunManagerBlueCFD as RunManager
 else:
     from .runmanager import RunManager

butterfly/gradingutil.py

@@ -1,4 +1,8 @@
 from collections import namedtuple
+try:
+    xrange(10)
+except:
+    xrange = range
 
 
 def secant(f, x0, x1, eps, ds, ln, n):