From PEP 8 - Style guide:
Use 4 spaces per indentation level.
For really old code that you don't want to mess up, you can continue to
use 8-space tabs.
Tabs or Spaces?
Never mix tabs and spaces.
The most popular way of indenting Python is with spaces only. The
second-most popular way is with tabs only. Code indented with a mixture
of tabs and spaces should be converted to using spaces exclusively.
Never mix tabs and spaces!
PgSQL.py (2.5.1) use:
tabs for even indentation levels and
zero o more tabs + four spaces for odd levels.
Seems good if you have 8 spaces tab setting in your editor, otherwise leads in mess code.