Create a function to check for criteria without data for the target v…

…olcano

With the changes in this commit, the new function check_for_criteria_
without_data() raises a PyvolcansError if there is any volcanological
criteria without data for the specific target volcano chosen by the
user to run PyVOLCANS. The associated warning message suggests to set
the weights for those criteria to zero.

pyvolcans/pyvolcans.py

@@ -26,6 +26,7 @@
     set_weights_from_args,
     open_gvp_website,
     output_result,
+    check_for_criteria_without_data,
     check_for_perfect_analogues,
     convert_to_idx,
     plot_bar_apriori_analogues,
@@ -114,15 +115,23 @@ def cli():
     # call PyVOLCANS
     try:
         # main PyVOLCANS result for all volcanoes (and weighting scheme used)
-        volcans_result = calculate_weighted_analogy_matrix(
-            volcano_input, weights=new_weights)
+        volcans_result, my_volcano_data = \
+            calculate_weighted_analogy_matrix(volcano_input,
+                                              weights=new_weights)
 
         # final PyVOLCANS result (specific of the target volcano selected)
         [top_analogues,
          volcano_name] = get_analogies(volcano_input,
                                        volcans_result,
                                        count)
 
+        # check for volcanological criteria without data for target volcano
+        try:
+            check_for_criteria_without_data(my_volcano_data, volcano_name)
+        except PyvolcansError as exc:
+            # do not quit the program in this situation
+            logging.warning(exc.args[0])
+
         # check for 'too many perfect analogues' (see Tierz et al., 2019)
         try:
             check_for_perfect_analogues(result=top_analogues)
@@ -141,7 +150,7 @@ def cli():
             volcans_result['smithsonian_id'].iloc[convert_to_idx(volcano_input)]
 
         # print main PyVOLCANS result to stdout
-        print(f"Top {count} analogue volcanoes for {volcano_name}, "
+        print(f"\nTop {count} analogue volcanoes for {volcano_name}, "
               f"{my_volcano_country} ({my_volcano_vnum}):")
         print(result)
 

pyvolcans/pyvolcans_func.py

@@ -365,7 +365,7 @@ def calculate_weighted_analogy_matrix(my_volcano, weights,
         particular run of PyVOLCANS. A different weighting scheme can generate
         an entirely different set of total analogy values.
 
-    my_volcano_data_dictionary: dict
+    my_volcano_data_dictionary : dict
         Dictionary containing information on whether there is volcanological
         data available (dict_value = 1), or there is not (dict_value = 0); for
         each of the volcanological criteria used by PyVOLCANS, considering the
@@ -422,7 +422,7 @@ def calculate_weighted_analogy_matrix(my_volcano, weights,
     volcans_result['ASt'] = \
         weighted_eruption_style_analogy[volcano_idx, ]
 
-    return volcans_result
+    return volcans_result, my_volcano_data_dictionary
 
 
 def get_analogies(my_volcano, volcans_result, count=10):
@@ -514,6 +514,50 @@ def check_for_perfect_analogues(result):
         raise PyvolcansError(msg)
 
 
+def check_for_criteria_without_data(my_volcano_data, my_volcano_name):
+    """
+    Assesses whether some volcanological criteria do not have any data for the
+    specific target volcano chosen by the user, raising a PyvolcansError
+    exception if this is the case, informing the user which are these criteria.
+
+    Parameters
+    ----------
+    my_volcano_name : str
+        Target volcano selected by the user, as volcano name.
+    my_volcano_data: dict
+        Dictionary containing information on whether there is volcanological
+        data available (dict_value = 1), or there is not (dict_value = 0); for
+        each of the volcanological criteria used by PyVOLCANS, considering the
+        specific target volcano chosen by the user to run the program.
+
+    Raises
+    -------
+    PyvolcansError
+        If one or more volcanological criteria have no data available for the
+        selected target volcano.
+    """
+
+    # based on:
+    # https://thispointer.com/python-how-to-find-keys-by-value-in-dictionary
+    my_list_keys = list()
+    my_list_items = my_volcano_data.items()
+    for item in my_list_items:
+        if item[1] == 0:
+            my_list_keys.append(item[0])
+
+    # check whether the list is not empty (in other words, there are some
+    # volcanological criteria without data)
+    if my_list_keys:
+        nodata_criteria_text = ', '.join(my_list_keys)
+        msg = ("WARNING!!! "
+               "The following volcanological criteria do not have "
+               "any data available for the selected target volcano "
+               f"({my_volcano_name}): {nodata_criteria_text}. Please "
+               "consider excluding these criteria from your weighting scheme "
+               "(i.e. setting their weights to zero).")
+        raise PyvolcansError(msg)
+
+
 def open_gvp_website(top_analogue_vnum):
     """
     Opens the GVP website for the top analogue volcano to the target volcano