None seems to work as a dictionary key, but I am wondering if that will just lead to trouble later. For example, this works: >>> x={'a':1, 'b':2, None:3} >>> x {'a': 1, None: 3, 'b': 2} >>> x[None] 3 The actual data I am working with is educational standards. Every standard is associated with a content area. Some standards are also associated with content subareas. I would like to make a nested dictionary of the form {contentArea:{contentSubArea:[standards]}}. Some of those contentSubArea keys would be None. In particular, I am wondering if this will lead to confusion if I look for a key that does not exist at some point, or something unanticipated like that. Continue reading...
