# get only the validator functions
sed -ne '/^def [[:alnum:]]*(field_data, all_data):/,/^$/p' |\
# change it to a class with only a clean method, add a call to super.clean()
sed -e 's;^def [a-z]*\([[:alnum:]]*\)(field_data, all_data):;class \1Field(CharField):\ndef clean(self, value):\n    value = CharField.clean(value);' |\
# change the indentation and add a return statement
sed -e 's;^    ;        ;' -e 's;^def clean;    def clean;' -e 's;^$;        return value\n;' |\
# rename the parameter to match convention
sed -e 's;field_data;value;g'