ruby instance variable in python

[roro codeath]

for instance in ruby i can write following code:

module M
def ins_var
@ins_var ||= nil
end

def m
@ins_var = "val"
end

def m2
ins_var # => "val"
end

end

in py

# m.py

# how to def a ins_var?

def m:
    # how to set a ins_var?

def m2:
    # how to get a ins_var?