add error handling for empty inputs

pages/join.py

@@ -1,4 +1,5 @@
 from pickle import FALSE
+from pages.utils import not_empty
 import streamlit as st
 import sqlite3
 import datetime
@@ -41,7 +42,10 @@ def app():
         
         submitted = st.form_submit_button("Submit")
 
-    if submitted and password1.strip() != password2.strip():
+    if empty(first_name) or empty(last_name) or empty(user_name) \ 
+        or empty(email) or empty(password1) or empty(password2):
+        st.warning("Complete all inputs.")
+    elif submitted and password1.strip() != password2.strip():
         st.warning("The passwords do not match.")
     elif user_name in usernames:
         st.warning("This user name already exists.")

pages/utils.py

@@ -6,6 +6,9 @@ import string
 import sqlite3
 import re
 
+def empty(string):
+  return len(string) == 0
+
 def add_blanks(word, sentence, blank = "__"):
   return re.sub(word, blank, sentence, flags=re.IGNORECASE)