3. Python Services

The modules described in this chapter provide a wide range of services related to the Python interpreter and its interaction with its environment. Here's an overview:

sys	Access system specific parameters and functions.
types	Names for all built-in types.
UserDict	Class wrapper for dictionary objects.
UserList	Class wrapper for list objects.
operator	All Python's standard operators as built-in functions.
traceback	Print or retrieve a stack traceback.
pickle	Convert Python objects to streams of bytes and back.
cPickle	Faster version of pickle, but not subclassable.
copy_reg	Register pickle support functions.
shelve	Python object persistency.
copy	Shallow and deep copy operations.
marshal	Convert Python objects to streams of bytes and back (with different constraints).
imp	Access the implementation of the import statement.
parser	Retrieve and submit parse trees from and to the runtime support environment.
symbol	Constants representing internal nodes of the parse tree.
token	Constants representing terminal nodes of the parse tree.
keyword	Test whether a string is a keyword in the Python language.
code	Code object services.
pprint	Data pretty printer.
dis	Disassembler.
site	A standard way to reference site-specific modules.
user	A standard way to reference user-specific modules.
__builtin__	The set of built-in functions.
__main__	The environment where the top-level script is run.