column += 1 can not be used in the way you are using it because it is a statement rather than an expression.
What you are writing is equivalent to self.test1 = input[column = column + 1] which doesn’t much sense.
Instead you would need to do:
column += 1
self.test1 = input[column]
or
self.test1 = input[column]
column += 1
depends on which one you were looking for.
Also, since you asked in your title, ++ or -- does not exist in python.
solved Python incremental int inplace ++ vs += [closed]