write a function that validates password

I have to write a function that validates a password and returns true or false. It is only true if it is 8 characters, contains a number, a upper case letter, and a symbol.

This is what I have for my function file.

def validatepassword(pswd):

for char in pswd: if char in '01234567890': containsnumber = True

I have no idea how to incorporate the other variables, any help is appreciated.

Thanks