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4.5 Types in Python

A big difference between Python and all other Common Lisp compilers is the approach to type checking and amount of knowledge about types:

• Python treats type declarations much differently that other Lisp compilers do. Python doesn’t blindly believe type declarations; it considers them assertions about the program that should be checked.
• Python also has a tremendously greater knowledge of the Common Lisp type system than other compilers. Support is incomplete only for the not, and and satisfies types.

See also sections advanced-type-stuff and type-inference.

• Compile Time Type Errors
• Precise Type Checking
• Weakened Type Checking