There is no ambiguity. If its indented consistently with the other lines in the block, its part of the block. Its fully, completely, utterly consistent.
For sanity, never use tabs for spacing, ever. Use Spaces. Never use anything but spaces, no matter what programming language you use. Different editors expand tabs differently. Just don't do it. Its damned bad practice.
All that said, stay with Python. If the only complaint is syntactically signifigant whitespace, I dare say we have a winner. Most languages people can come up with a hell of a lot more important (and valid) things to complain about.