Two of the most useful methods on strings involve lists of strings. The split method breaks a string into a list of words. By default, any number of whitespace characters is considered a word boundary.
An optional argument called a delimiter can be used to specify which characters to use as word boundaries. The following example uses the string ai as the delimiter:
Notice that the delimiter doesn’t appear in the result.
The inverse of the split method is join. You choose a desired separator string, (often called the glue) and join the list with the glue between each of the elements.
The list that you glue together (wds in this example) is not modified. Also, you can use empty glue or multi-character strings as glue.