Clean up the logic of fill_priors and close #58

• Removes the 'bad_keys' part of the logic. I believe this was essentially adding the keys which where not given in the prior and that had no default prior, and then removing them at the end.
• Change the logging output slightly: now the only warning that is given is when no default prior is known. Other output at info level
• Add in what the waveform_generator knows about missing keys (useful for diagnosis
• Formatting of the docstring

tupak/prior.py

@@ -403,6 +403,8 @@ def create_default_prior(name):
     if name in default_priors.keys():
         prior = default_priors[name]
     else:
+        logging.info(
+            "No default prior found for variable {}.".format(name))
         prior = None
     return prior
 
@@ -430,40 +432,48 @@ def parse_keys_to_parameters(keys):
 
 def fill_priors(prior, waveform_generator):
     """
-    Fill dictionary of priors based on required parameters for waveform generator
+    Fill dictionary of priors based on required parameters of waveform generator
+
+    Any floats in prior will be converted to delta function prior. Any
+    required, non-specified parameters will use the default.
 
-    Any floats in prior will be converted to delta function prior.
-    Any required, non-specified parameters will use the default.
     Parameters
     ----------
     prior: dict
         dictionary of prior objects and floats
     waveform_generator: WaveformGenerator
         waveform generator to be used for inference
+
+    Returns
+    -------
+    prior: dict
+        The filled prior dictionary
+
     """
-    bad_keys = []
+
     for key in prior:
         if isinstance(prior[key], Prior):
             continue
         elif isinstance(prior[key], float) or isinstance(prior[key], int):
             prior[key] = DeltaFunction(prior[key])
-            logging.info("{} converted to delta function prior.".format(key))
+            logging.info(
+                "{} converted to delta function prior.".format(key))
         else:
-            logging.warning("{} cannot be converted to delta function prior.".format(key))
-            logging.warning("If required the default prior will be used.")
-            bad_keys.append(key)
+            logging.info(
+                "{} cannot be converted to delta function prior.".format(key))
 
     missing_keys = set(waveform_generator.parameters) - set(prior.keys())
 
     for missing_key in missing_keys:
-        prior[missing_key] = create_default_prior(missing_key)
-        if prior[missing_key] is None:
-            logging.warning("No default prior found for unspecified variable {}.".format(missing_key))
-            logging.warning("This variable will NOT be sampled.")
-            bad_keys.append(missing_key)
-
-    for key in bad_keys:
-        prior.pop(key)
+        default_prior = create_default_prior(missing_key)
+        if default_prior is None:
+            set_val = waveform_generator.parameters[missing_key]
+            logging.warning(
+                "Parameter {} has no default prior and is set to {}, this will"
+                " not be sampled and may cause an error."
+                .format(missing_key, set_val))
+        else:
+            prior[missing_key] = default_prior
 
     return prior