Insert characters into string based on re ?

[Matt]

I am attempting to reformat a string, inserting newlines before certain
phrases. For example, in formatting SQL, I want to start a new line at
each JOIN condition. Noting that strings are immutable, I thought it
best to spllit the string at the key points, then join with '\n'.

Regexps can seem the best way to identify the points in the string
('LEFT.*JOIN' to cover 'LEFT OUTER JOIN' and 'LEFT JOIN'), since I need
to identify multiple locationg in the string. However, the re.split
method returns the list without the split phrases, and re.findall does
not seem useful for this operation.

Suggestions?