cleanup

app.py

@@ -16,7 +16,8 @@ st.session_state['userInput'] = st.text_input('Enter a target transcript (or sub
 
 # input is too short
 if len(st.session_state['userInput']) < GUIDE_LEN:
-    st.write('Transcript length ({:d}) must be >= 23 bases.'.format(len(st.session_state['userInput'])))
+    transcript_len = len(st.session_state['userInput'])
+    st.write('Transcript length ({:d}) must be at least {:d} bases.'.format(transcript_len, GUIDE_LEN))
 
 # valid input
 elif all([True if nt.upper() in NUCLEOTIDE_TOKENS.keys() else False for nt in st.session_state['userInput']]):