[+] Environ.__contains__(), so checks are more intuitive. [*] make checks more intuitive :).
[+] some doc about the attributes.
[*] test and fix class instantiation.
[+] initial version of a ast -> code pprinter.
[*] pprint() prints itself, more or less.
[*] pprint() prints itself, more than before :).
[*] some refactoring. [*] pprint() prints ayrton/expansion.py. [*] no spurious commas.
[*] modified pprint_seq() so we can implement BoolOp with it.
[*] more stuff.
[*] more stuff. [*] fix bug in pprint_seq(). [*] typo in Dict.
[*] pprint() prints cpython/Lib/ast.py :)
[+] LShift and DictComp.
[*] fix optional exception in ExceptHandler and Raise.
[*] more proper but not perfect argument printing.