Handle bytes/string conversion

handel/interface.py

@@ -7,11 +7,29 @@ import numpy
 from .error import check_return_value, check_error
 from ._cffi import handel, ffi
 
+__all__ = ['init', 'init_handel', 'exit',
+           'new_detector', 'get_num_detectors', 'get_detectors',
+           'start_run', 'stop_run', 'get_run_data_length', 'get_run_data',
+           'load_system', 'save_system', 'start_system',
+           'enable_log_output', 'disable_log_output',
+           'set_log_output', 'set_log_level', 'close_log',
+           'set_acquisition_value', 'get_acquisition_value',
+           'get_handel_version']
+
+
+# Helpers
+
+def to_bytes(arg):
+    if isinstance(arg, bytes):
+        return arg
+    return arg.encode()
+
 
 # Initializing handel
 
 @check_return_value
 def init(filename):
+    filename = to_bytes(filename)
     return handel.xiaInit(filename)
 
 
@@ -29,6 +47,7 @@ def exit():
 
 @check_return_value
 def new_detector(alias):
+    alias = to_bytes(alias)
     return handel.xiaNewDetector(alias)
 
 
@@ -42,7 +61,7 @@ def get_detectors():
     n = get_num_detectors()
     arg = [ffi.new('char []', 80) for _ in range(n)]
     check_error(handel.xiaGetDetectors(arg))
-    return tuple(ffi.string(x) for x in arg)
+    return tuple(ffi.string(x).decode() for x in arg)
 
 
 # int xiaAddDetectorItem(char *alias, char *name, void *value);
@@ -88,12 +107,14 @@ def get_run_data(channel):
 @check_return_value
 def load_system(filename):
     # Is this an alias to xiaInit?
-    return handel.xiaLoadSystem('handel_ini', filename)
+    filename = to_bytes(filename)
+    return handel.xiaLoadSystem(b'handel_ini', filename)
 
 
 @check_return_value
 def save_system(filename):
-    return handel.xiaSaveSystem('handel_ini', filename)
+    filename = to_bytes(filename)
+    return handel.xiaSaveSystem(b'handel_ini', filename)
 
 
 @check_return_value
@@ -120,6 +141,7 @@ def set_log_level(level):
 
 @check_return_value
 def set_log_output(filename):
+    filename = to_bytes(filename)
     return handel.xiaSetLogOutput(filename)
 
 
@@ -165,11 +187,13 @@ def close_log():
 # Parameters
 
 def set_acquisition_value(channel, name, value):
+    name = to_bytes(name)
     pointer = ffi.new('double *', value)
     check_error(handel.xiaSetAcquisitionValues(channel, name, pointer))
 
 
 def get_acquisition_value(channel, name):
+    name = to_bytes(name)
     pointer = ffi.new('double *')
     check_error(handel.xiaGetAcquisitionValues(channel, name, pointer))
     return pointer[0]
@@ -202,7 +226,7 @@ def get_acquisition_value(channel, name):
 # Debugging
 
 
-def get_version_info():
+def get_handel_version():
     rel = ffi.new('int *')
     min = ffi.new('int *')
     maj = ffi.new('int *')

tests/test_interface.py

@@ -17,7 +17,11 @@ def test_init(interface):
     m = interface.handel.xiaInit
     m.return_value = 0
     assert interface.init('somefile') is None
-    m.assert_called_once_with('somefile')
+    m.assert_called_once_with(b'somefile')
+    m.reset_mock()
+    # Should work with bytes too
+    assert interface.init(b'somefile') is None
+    m.assert_called_once_with(b'somefile')
 
 
 def test_init_handel(interface):
@@ -40,7 +44,7 @@ def test_new_detector(interface):
     m = interface.handel.xiaNewDetector
     m.return_value = 0
     assert interface.new_detector('somealias') is None
-    m.assert_called_once_with('somealias')
+    m.assert_called_once_with(b'somealias')
 
 
 def test_get_num_detectors(interface):
@@ -73,7 +77,7 @@ def test_get_detectors(interface):
 
     m1.side_effect = side_effect_1
     m2.side_effect = side_effect_2
-    expected = b'name1', b'name2', b'name3'
+    expected = 'name1', 'name2', 'name3'
     assert interface.get_detectors() == expected
     m2.assert_called_once()
     arg = m2.call_args[0][0]
@@ -144,14 +148,14 @@ def test_load_system(interface):
     m = interface.handel.xiaLoadSystem
     m.return_value = 0
     assert interface.load_system('somefile') is None
-    m.assert_called_once_with('handel_ini', 'somefile')
+    m.assert_called_once_with(b'handel_ini', b'somefile')
 
 
 def test_save_system(interface):
     m = interface.handel.xiaSaveSystem
     m.return_value = 0
     assert interface.save_system('somefile') is None
-    m.assert_called_once_with('handel_ini', 'somefile')
+    m.assert_called_once_with(b'handel_ini', b'somefile')
 
 
 def test_start_system(interface):
@@ -188,7 +192,7 @@ def test_set_log_output(interface):
     m = interface.handel.xiaSetLogOutput
     m.return_value = 0
     assert interface.set_log_output('somefile') is None
-    m.assert_called_once_with('somefile')
+    m.assert_called_once_with(b'somefile')
 
 
 def test_close_log(interface):
@@ -205,7 +209,7 @@ def test_set_acquisition_value(interface):
     m.return_value = 0
     assert interface.set_acquisition_value(1, 'test', 2.3) is None
     arg = m.call_args[0][2]
-    m.assert_called_once_with(1, 'test', arg)
+    m.assert_called_once_with(1, b'test', arg)
     assert arg[0] == 2.3
 
 
@@ -219,17 +223,17 @@ def test_get_acquistion_value(interface):
     m.side_effect = side_effect
     assert interface.get_acquisition_value(1, 'test') == 2.3
     arg = m.call_args[0][2]
-    m.assert_called_once_with(1, 'test', arg)
+    m.assert_called_once_with(1, b'test', arg)
 
 
 # Debugging
 
-def test_get_version_info(interface):
+def test_get_handel_version(interface):
     m = interface.handel.xiaGetVersionInfo
 
     def side_effect(a, b, c, d):
         d[0], c[0], b[0], a[0] = b'v', 1, 2, 3
 
     m.side_effect = side_effect
-    assert interface.get_version_info() == (1, 2, 3)
+    assert interface.get_handel_version() == (1, 2, 3)
     m.assert_called_once()