validation - Python: Input validate with string length

Question

Ok so i need to ensure that a phone number length is correct. I came up with this but get a syntax error.

phone = int(input("Please enter the customer's Phone Number."))
if len(str(phone)) == 11:
    else: phone = int(input("Please enter the customer's Phone Number."))
phonumber.append(phone)

Answer 1

You can't have

if:
    else:

Because the else, being inside the first if block, doesn't have a corresponding if.

It should be:

if:
    this
else:
    that