C. Titus Brown wrote:
over on the pygr list, we were recently discussing a mildly confusing
edit I made:
assert 'seq1' in self.db, self.db.keys()
This was interpreted by someone as being
assert 'seq1' in (self.db, self.db.keys())
which is very different from the actual meaning,
assert ('seq1' in self.db), self.db.keys()
where 'self.db.keys()' serves as the message to be printed out when the
assertion fails. Apart from questions of why I was apparently out to
confuse people with this edit, the question of ',' precedence came up.
Looking at
http://docs.python.org/ref/summary.html
there's no mention of ',' binding and tuple creation vs the other
operators.
A bare "," is part of the "expression list" syntax; it's not an operator:
http://docs.python.org/ref/exprlists.html
You have to look at the statement descriptions to find out whether a
statement wants an expression or an expression list (e.g. "return" takes
an expression list, while "assert" takes two expressions, not two
expression lists).
</F>
_______________________________________________
Python-Dev mailing list
Python-Dev@python.org
http://mail.python.org/mailman/listinfo/python-dev
Unsubscribe:
http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
