Fix for __str__ returned non-string error

app/admin.py

@@ -99,6 +99,25 @@ class RangeNameTranslationAdmin(admin.ModelAdmin):
     search_fields = ['range_name_translation']
 
 
+class PeopleRangeAdmin(admin.ModelAdmin):
+    model = Range
+    list_display = ['person', 'range_name', ]
+
+    def range_name(self, obj):
+        return str(obj.range.name)
+
+
+class RangeCountryAdmin(admin.ModelAdmin):
+    model = RangeCountry
+    search_fields = ['range__range_name', 'country__short_name']
+    list_display = ['range_name', 'country_name']
+
+    def range_name(self, obj):
+        return str(obj.range.range_name)
+
+    def country_name(self, obj):
+        return str(obj.country.short_name) if obj.country else 'None'
+
 
 # Register your models here.
 admin.site.register(Person, PersonAdmin)
@@ -136,13 +155,13 @@ admin.site.register(ImportGeom210915)
 admin.site.register(Peak, PeaksAdmin)
 admin.site.register(Search, SearchAdmin)
 admin.site.register(TaxaPeople)
-admin.site.register(RangesPeople)
-admin.site.register(ResourcesPeople)
+# admin.site.register(RangesPeople)
+# admin.site.register(ResourcesPeople)
 admin.site.register(ScalesPeople)
 admin.site.register(Species, SpeciesAdmin)
 admin.site.register(PeopleFunction)
 admin.site.register(SpeciesRange)
-admin.site.register(PeopleRange)
+admin.site.register(RangesPeople, PeopleRangeAdmin)
 admin.site.register(TaxonRange, TaxonRangeAdmin)
 admin.site.register(PeopleResource)
-admin.site.register(RangeCountry)
+admin.site.register(RangeCountry, RangeCountryAdmin)

app/models.py

@@ -119,7 +119,7 @@ class Range(models.Model):
         db_table = 'range'
 
     def __str__(self):
-        return self.name
+        return self.range_name if self else '--'
 
     def dict(self):
         return {
@@ -210,7 +210,7 @@ class Country(models.Model):
     iso2 = models.TextField(blank=True, null=True)
 
     def __str__(self):
-        return self.formal_name
+        return self.short_name if self else '--'
 
 
 class GMBA_SpeciesGroup(models.Model):
@@ -657,7 +657,7 @@ class PeopleRange(models.Model):
     range = models.ForeignKey(Range, models.DO_NOTHING, blank=True, null=True)
 
     def __str__(self):
-        return self.person.full_name
+        return str(self.id)
 
 
 class TaxonRange(models.Model):
@@ -684,7 +684,7 @@ class PeopleResource(models.Model):
     role = models.TextField(blank=True, null=True)
 
     def __str__(self):
-        return self.person.full_name
+        return self.person.full_name if self.person else ' -- '
 
 
 class RangeCountry(models.Model):
@@ -693,4 +693,4 @@ class RangeCountry(models.Model):
     country = models.ForeignKey(Country, models.DO_NOTHING, blank=True, null=True)
 
     def __str__(self):
-        return self.range.name
+        return '%s --- %s' % (self.range.range_name if self.range else 'None', self.country.short_name if self.country else 'None')