def find_source(node):
    """Locate source code for *node*. Returns a list of strings."""
    if node.filename == '' or node.filename is None:
        return
    lines = open(node.filename, 'r').readlines()
    if isinstance(node.lineno, slice):
        lineno = slice(node.lineno.start - 1, node.lineno.stop - 1)
    else:
        lineno = node.lineno - 1
    return lines[lineno]
