(a, b, c).join(',')
instead of: ','.join((a, b, c))
>>> "abcbe".split("b") ['a', 'c', 'e']
['a', 'c', 'e'].join("b") #!!! WRONG !!!
>>> "b".join(['a', 'c', 'e']) 'abcbe'
br = '<br>'.join
br((a, b, c))
Personally I think it makes more sense the ruby way but it's never bugged me.
def br(sl): return string.join(sl, "<br>")
br = lambda sl: string.join(sl, "<br>")
(a, b, c).join(',')
instead of: ','.join((a, b, c))