Fix 500 during contact search; add comments and format files

app.py

@@ -12,6 +12,8 @@
 
 app = Flask(__name__)
 
+# WARNING: Do not put your secret key in the code for real applications!
+# Use an environment variable instead to keep it secret
 app.secret_key = b'hypermedia rocks'
 
 
@@ -96,7 +98,8 @@ def contacts_edit_get(contact_id=0):
 @app.route("/contacts/<contact_id>/edit", methods=["POST"])
 def contacts_edit_post(contact_id=0):
     c = Contact.find(contact_id)
-    c.update(request.form['first_name'], request.form['last_name'], request.form['phone'], request.form['email'])
+    c.update(request.form['first_name'], request.form['last_name'],
+             request.form['phone'], request.form['email'])
     if c.save():
         flash("Updated Contact!")
         return redirect("/contacts/" + str(contact_id))
@@ -163,7 +166,8 @@ def json_contacts_view(contact_id=0):
 @app.route("/api/v1/contacts/<contact_id>", methods=["PUT"])
 def json_contacts_edit(contact_id):
     c = Contact.find(contact_id)
-    c.update(request.form['first_name'], request.form['last_name'], request.form['phone'], request.form['email'])
+    c.update(request.form['first_name'], request.form['last_name'],
+             request.form['phone'], request.form['email'])
     if c.save():
         return c.__dict__
     else:

contacts_model.py

@@ -10,6 +10,7 @@
 # ========================================================
 PAGE_SIZE = 100
 
+
 class Contact:
     # mock contacts database
     db = {}
@@ -34,7 +35,8 @@ def update(self, first, last, phone, email):
     def validate(self):
         if not self.email:
             self.errors['email'] = "Email Required"
-        existing_contact = next(filter(lambda c: c.id != self.id and c.email == self.email, Contact.db.values()), None)
+        existing_contact = next(filter(
+            lambda c: c.id != self.id and c.email == self.email, Contact.db.values()), None)
         if existing_contact:
             self.errors['email'] = "Email Must Be Unique"
         return len(self.errors) == 0
@@ -72,7 +74,7 @@ def all(cls, page=1):
     def search(cls, text):
         result = []
         for c in cls.db.values():
-            if text in c.first or text in c.last or text in c.email or text in c.phone:
+            if (c.first != None and text in c.first) or (c.last != None and text in c.last) or (c.email != None and text in c.email) or (c.phone != None and text in c.phone):
                 result.append(c)
         return result
 
@@ -82,7 +84,8 @@ def load_db(cls):
             contacts = json.load(contacts_file)
             cls.db.clear()
             for c in contacts:
-                cls.db[c['id']] = Contact(c['id'], c['first'], c['last'], c['phone'], c['email'])
+                cls.db[c['id']] = Contact(
+                    c['id'], c['first'], c['last'], c['phone'], c['email'])
 
     @staticmethod
     def save_db():