Python conditional assignment operator

Question

Does a Python equivalent to the Ruby ||= operator ("set the variable if the variable is not set") exist?

Example in Ruby :

 variable_not_set ||= 'bla bla'  variable_not_set == 'bla bla'   variable_set = 'pi pi'  variable_set ||= 'bla bla'  variable_set == 'pi pi' 

Answer 1

I'm surprised no one offered this answer. It's not as "built-in" as Ruby's ||= but it's basically equivalent and still a one-liner:

foo = foo if 'foo' in locals() else 'default' 

Of course, locals() is just a dictionary, so you can do:

foo = locals().get('foo', 'default')