make aligned spin priors load and cosmological safer

bilby/core/prior.py

@@ -104,6 +104,11 @@ class PriorDict(OrderedDict):
         Notes
         -----
         Lines beginning with '#' or empty lines will be ignored.
+        Priors can be loaded from:
+            bilby.core.prior as, e.g.,    foo = Uniform(minimum=0, maximum=1)
+            floats, e.g.,                 foo = 1
+            bilby.gw.prior as, e.g.,      foo = bilby.gw.prior.AlignedSpin()
+            other external modules, e.g., foo = my.module.CustomPrior(...)
         """
 
         comments = ['#', '\n']
@@ -118,6 +123,13 @@ class PriorDict(OrderedDict):
                 val = '='.join(elements[1:]).strip()
                 cls = val.split('(')[0]
                 args = '('.join(val.split('(')[1:])[:-1]
+                try:
+                    prior[key] = DeltaFunction(peak=float(cls))
+                    logger.debug("{} converted ot DeltaFunction prior".format(
+                        key))
+                    continue
+                except ValueError:
+                    pass
                 if "." in cls:
                     module = '.'.join(cls.split('.')[:-1])
                     cls = cls.split('.')[-1]
@@ -676,6 +688,11 @@ class Prior(object):
 
     @classmethod
     def from_repr(cls, string):
+        """Generate the prior from it's __repr__"""
+        return cls._from_repr(string)
+
+    @classmethod
+    def _from_repr(cls, string):
         subclass_args = infer_args_from_method(cls.__init__)
 
         string = string.replace(' ', '')
@@ -696,20 +713,25 @@ class Prior(object):
         remove = list()
         for ii, key in enumerate(args):
             if '(' in key:
-                args[ii] = ','.join([args[ii], args[ii + 1]]).strip()
-                remove.append(ii + 1)
+                jj = ii
+                while ')' not in args[jj]:
+                    jj += 1
+                    args[ii] = ','.join([args[ii], args[jj]]).strip()
+                    remove.append(jj)
         remove.reverse()
         for ii in remove:
             del args[ii]
         kwargs = dict()
         for ii, arg in enumerate(args):
-            try:
-                key, val = arg.split('=')
-            except ValueError:
+            if '=' not in arg:
                 logger.debug(
                     'Reading priors with non-keyword arguments is dangerous!')
                 key = subclass_args[ii]
                 val = arg
+            else:
+                split_arg = arg.split('=')
+                key = split_arg[0]
+                val = '='.join(split_arg[1:])
             kwargs[key] = val
         return kwargs
 

bilby/gw/prior.py

@@ -149,6 +149,17 @@ class Cosmological(Interped):
     def _get_redshift_arrays(self):
         raise NotImplementedError
 
+    @classmethod
+    def from_repr(cls, string):
+        if "FlatLambdaCDM" in string:
+            logger.warning(
+                "Cosmological priors cannot be loaded from a string. "
+                "If the prior has a name, use that instead."
+            )
+            return string
+        else:
+            return cls._from_repr(string)
+
 
 class UniformComovingVolume(Cosmological):