Python3 has a pass command that does nothing. This command is used in if-constructs because python requires the programmer to have at least one command for else. Does Ruby have an equivalent to python3's pass command?
Your statement is essentially wrong, since else statement is not obligatory in Python.
One of the frequent uses of the pass statement is in try/ except construct, when exception may be ignored.
pass is also useful when you define API - and wish to postpone actual implementation of classes/functions.
EDIT:
One more frequent usage I haven't ,mentioned - defining user exception; usually you just override name to distinguish them from standard exceptions.
Python3 Pass Command Equivalent in Ruby