Unlike C, Python does not support in-line assignment, so there's no chance of accidentally assigning the value you thought you were comparing. A dictionary in Python is like a hash in Perl. A dictionary in Python is like an instance of the Hashtable class in Java. A dictionary in Python is like an instance of the Scripting. Dictionary object in Visual Basic.
Dictionaries have no concept of order among elements.
There are ways of doing this, they're just not built into the dictionary. A list in Python is like an array in Perl. A better analogy would be to the Vector class, which can hold arbitrary objects and can expand dynamically as new items are added. There is no boolean datatype in Python. This extends to other datatypes, too.