easy question about join method

[Terry Reedy]

The easy way to get one answer for buildin funcs and methods is the help 
function in the interactive interpreter (and Idle's and probably other 
imitations thereof) is, for example,

>>> help(str.join)
Help on method_descriptor:

join(...)
    S.join(sequence) -> string

    Return a string which is the concatenation of the strings in the
    sequence.  The separator between elements is S.

To remind how to use 'help', 'help' is more informative than 'help(help)' 
;-)

Terry Jan Reedy