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(python2.1-lib.info)Queries on AST Objects

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Queries on AST Objects
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Two functions are provided which allow an application to determine if
an AST was created as an expression or a suite.  Neither of these
functions can be used to determine if an AST was created from source
code via `expr()' or `suite()' or from a parse tree via
`sequence2ast()'.

`isexpr(ast)'
     When AST represents an `'eval'' form, this function returns true,
     otherwise it returns false.  This is useful, since code objects
     normally cannot be queried for this information using existing
     built-in functions.  Note that the code objects created by
     `compileast()' cannot be queried like this either, and are
     identical to those created by the built-in `compile()'  function.

`issuite(ast)'
     This function mirrors `isexpr()' in that it reports whether an AST
     object represents an `'exec'' form, commonly known as a "suite."
     It is not safe to assume that this function is equivalent to `not
     isexpr(AST)', as additional syntactic fragments may be supported
     in the future.