Insert characters into string based on re ?

[harvey.thomas at informa.com]

Matt wrote:
> 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?

I think that re.sub is a more appropriate method rather than split and
join

trivial example (non SQL):

>>> addnlre = re.compile('LEFT\s.*?\s*JOIN|RIGHT\s.*?\s*JOIN', re.DOTALL + re.IGNORECASE).sub
>>> addnlre(lambda x: x.group() + '\n', '... LEFT JOIN x RIGHT OUTER join y')
'... LEFT JOIN\n x RIGHT OUTER join\n y'