Correct common misspelling of codes

france/france_rsvp/codes.py

@@ -11,6 +11,19 @@ assert len(ALPHABET) == 32
 LENGTH = 4
 
 
+CORRECT = {
+    'i': '1',
+    'l': '1',
+    'o': '0',
+}
+
+
+def correct_code(code):
+    code = code.lower()
+    fixed_code = ''.join(CORRECT.get(c, c) for c in code)
+    return fixed_code
+
+
 def list_errors(code):
     for place in range(LENGTH):
         for replacement in ALPHABET:

france/france_rsvp/web.py

@@ -2,6 +2,7 @@ from flask import Flask, render_template, request, url_for
 import logging
 from werkzeug.utils import redirect
 
+from .codes import correct_code
 from .database import get_name_and_replies, record_reply
 
 
@@ -18,7 +19,7 @@ def form():
             'code' in request.form
             and len(request.form['code']) == 4
         ):
-            code = request.form['code']
+            code = correct_code(request.form['code'])
             try:
                 get_name_and_replies(code)
             except ValueError: