def explodeChars(s, sChar=" ", last=False):
if not len(sChar) == 1:
raise ValueError, "len(sChar) must be 1"
seps = [sChar] * len(s)
r = ["%s%s" % i for i in zip(s, seps)]
if last:
return "".join(r)
else:
return "".join(r)[:-1]
if __name__ == "__main__":
s = "abcde"
print explodeChars(s)
print explodeChars(s, "@", False)
print explodeChars(s, "_", True)
#print explodeChars(s, "**")