avoid using len(x) to check if empty

voseq/public_interface/forms.py

@@ -151,7 +151,7 @@ def search(self):
                 sqs = SearchQuerySet().using('vouchers').filter(**keywords)
                 print(sqs)
 
-        if len(sqs) > 0:
+        if sqs:
             return sqs
         else:
             self.no_query_found()

voseq/public_interface/management/commands/_migrate_db.py

@@ -398,7 +398,7 @@ def save_table_sequences_to_db(self):
             print("Uploading table `public_interface_sequences`")
         Sequences.objects.bulk_create(seqs_objects)
 
-        if len(seqs_not_to_insert) > 0:
+        if seqs_not_to_insert:
             if self.verbosity != 0:
                 print("ERROR: Couldn't insert %i sequences due to lack of reference vouchers".format(len(seqs_not_to_insert)))
             for i in seqs_not_to_insert:

voseq/view_genes/views.py

@@ -46,10 +46,10 @@ def gene(request, gene_code):
     username = get_username(request)
 
     queryset = Genes.objects.filter(gene_code=gene_code)
-    if len(queryset) < 1:
-        item = ''
-    else:
+    if queryset:
         item = queryset[0]
+    else:
+        item = ''
 
         if ';' in item.intron:
             introns = item.intron.split(';')