ValueError: unsupported format character '{' (0x7b) in defining dictionary

I'm writing some code for web development using Google Python Appengine. In my code I have to concatenate strings using % and dictionary Here's the code I've written. ``` def print_form(self, unameError='', passwdError='', verpasswdError='', emailError='', unameValue='', emailValue='' ): self.response.out.write( form3 % { "unameError" : unameError, "passwdError" : passwdError, "verpasswdError": verpasswdError, "emailError" : emailError, "unameValue" : unameValue, "emailValue" : emailValue } ) ``` For this code, I'm receiving this error from server : web-app-local-directory-path/main.py", line 139, in print_form "emailValue" : emailValue ValueError: unsupported format character '{' (0x7b) at index 218 I can't seem to figure out what is wrong in this code. I've defined a valid dictionary and there seem to be no problem with it according to me. Somebody please help me on this. Regards Vaid, Abhishek