Does a Python equivalent to the Ruby ||= operator (\"set the variable if the variable is not set\") exist?
||=
Example in Ruby :
variable_n
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')