import re
s = """\
This is entry 1.
This
is
entry 2.
And this is entry 3.
This
is
entry
4."""
s = re.sub("[^\S\n]*\n[^\S\n]+", " ", s).split("\n");
print s
aW1wb3J0IHJlCgpzID0gIiIiXApUaGlzIGlzIGVudHJ5IDEuClRoaXMKIGlzCiAgZW50cnkgMi4KQW5kIHRoaXMgaXMgZW50cnkgMy4KVGhpcwogaXMKIGVudHJ5CiA0LiIiIgpzID0gcmUuc3ViKCJbXlxTXG5dKlxuW15cU1xuXSsiLCAiICIsIHMpLnNwbGl0KCJcbiIpOwpwcmludCBz