Use select_config in AFMPiezo's doctests.

diff --git a/pypiezo/afm.py b/pypiezo/afm.py
index fc74e1fc9d2823af1c793d008abd3b3ee2c858f2..049d4a882c3e4e4f11a9a84c476f805556a1229c 100644 (file)
--- a/pypiezo/afm.py
+++ b/pypiezo/afm.py
@@ -96,7 +96,8 @@ class AFMPiezo (_base.Piezo):
     We need to know where we are before we can move somewhere
     smoothly.
 
-    >>> pos = _base.convert_volts_to_bits(p.config['axes'][0]['channel'], 0)
+    >>> pos = _base.convert_volts_to_bits(p.config.select_config(
+    ...     'axes', 'z')['channel'], 0)
     >>> p.jump('z', pos)
 
     Usually `.move_to_pos_or_def` is used to approach the surface, but
@@ -104,9 +105,10 @@ class AFMPiezo (_base.Piezo):
     into the deflection input channel.
 
     >>> target_pos = _base.convert_volts_to_bits(
-    ...     p.config['axes'][0]['channel'], 2)
+    ...     p.config.select_config('axes', 'channel'), 2)
     >>> step = int((target_pos - pos)/5)
-    >>> target_def = _base.convert_volts_to_bits(p.config['inputs'][0], 3)
+    >>> target_def = _base.convert_volts_to_bits(
+    ...     p.config.select_config('inputs', 'deflection'), 3)
     >>> data = p.move_to_pos_or_def('z', target_pos, target_def, step=step,
     ...     return_data=True)
     >>> p.last_output == {'z': int(target_pos)}
@@ -122,7 +124,7 @@ class AFMPiezo (_base.Piezo):
 
     >>> p.jump('z', pos)
     >>> target_def = _base.convert_volts_to_bits(
-    ...     p.config['inputs'][0], 1)
+    ...     p.config.select_config('inputs', 'deflection'), 1)
     >>> data = p.move_to_pos_or_def('z', target_pos, target_def, step=step,
     ...     return_data=True)
     >>> print (p.last_output['z'] < int(target_pos))