n = 1
p = 4
print n += p
gives me:
File "p7.py", line 17
print n += p
SyntaxError: invalid syntax
How can this problem be fixed?
n += p is a statement in Python, not an expression that returns a value you could print. This is different from a couple of other languages, for example Ruby, where everything is an expression.
You need to do
n += p
print n