programs.get_version: now raises ImportError when module is not installed (the

previous return values were ambiguous: was returning version number is module
was installed, None if module was installed but version number could not be
retrieved, and False when module was not installed). The old implementation has
lead to a bug when trying to handle missing pylint dependency which is fixed by
this revision too.

Author: PierreRaybaut

spyderlib/dependencies.py

@@ -28,7 +28,11 @@ def __init__(self, modname, features, required_version,
         self.features = features
         self.required_version = required_version
         if installed_version is None:
-            self.installed_version = programs.get_module_version(modname)
+            try:
+                self.installed_version = programs.get_module_version(modname)
+            except ImportError:
+                # Module is not installed
+                self.installed_version = None
         else:
             self.installed_version = installed_version
 

spyderlib/utils/programs.py

@@ -202,14 +202,8 @@ def check_version(actver, version, cmp_op):
 
 
 def get_module_version(module_name):
-    """Get module version.
-    
-    Return module version, return False if module is not installed,
-    return None if module is installed but version can't be retrieved"""
-    try:
-        mod = __import__(module_name)
-    except ImportError:
-        return False
+    """Return module version or None if version can't be retrieved."""
+    mod = __import__(module_name)
     return getattr(mod, '__version__', getattr(mod, 'VERSION', None))
 
 
@@ -262,8 +256,9 @@ def is_module_installed(module_name, version=None, installed_version=None,
             return True
     else:
         if installed_version is None:
-            actver = get_module_version(module_name)
-            if actver is not None and not actver:
+            try:
+                actver = get_module_version(module_name)
+            except ImportError:
                 # Module is not installed
                 return False
         else:

spyderlib/widgets/dependencies.py

@@ -153,9 +153,9 @@ def test():
     from spyderlib import dependencies
 
     # Test sample
-    dependencies.add("IPython", "Enhanced Python interpreter", ">=0.13")
-    dependencies.add("matplotlib", "Interactive data plotting", ">=1.0")
-    dependencies.add("sympy", "Symbolic Mathematics", ">=10.0")
+#    dependencies.add("IPython", "Enhanced Python interpreter", ">=0.13")
+#    dependencies.add("matplotlib", "Interactive data plotting", ">=1.0")
+#    dependencies.add("sympy", "Symbolic Mathematics", ">=10.0")
     dependencies.add("foo", "Non-existent module", ">=1.0")
 
     from spyderlib.utils.qthelpers import qapplication