add simple email validator to form to prevent spam

wowstash/forms.py

@@ -1,4 +1,6 @@
 from re import match as re_match
+from re import fullmatch as re_fullmatch
+from re import compile as re_compile
 from flask_wtf import FlaskForm
 from wtforms import StringField, BooleanField
 from wtforms.validators import DataRequired, ValidationError
@@ -11,6 +13,12 @@ class Register(FlaskForm):
     terms_reviewed = BooleanField('Terms Reviewed:', validators=[DataRequired()], render_kw={"class": "form-control-span"})
     privacy_reviewed = BooleanField('Privacy Policy Reviewed:', validators=[DataRequired()], render_kw={"class": "form-control-span"})
 
+    def validate_email(self, email):
+        regex = re_compile(r'([A-Za-z0-9]+[.-_])*[A-Za-z0-9]+@[A-Za-z0-9-]+(\.[A-Z|a-z]{2,})+')
+        if not re_fullmatch(regex, self.email.data):
+          raise ValidationError('This appears to be an invalid email. Contact admins if you feel this is incorrect.')
+
+
 class Login(FlaskForm):
     email = StringField('Email Address:', validators=[DataRequired()], render_kw={"placeholder": "Email", "class": "form-control", "type": "email"})
     password = StringField('Password:', validators=[DataRequired()], render_kw={"placeholder": "Password", "class": "form-control", "type": "password"})