SYNTAX TREE DISPLAY IN PYTHON.

class NAMESPACE:
    def __init__( SELF, **KWARGS ):
        SELF.__dict__.update( KWARGS )

import ast as AST
ROOT= AST.parse( open( "../PRIME_SIEVE.PY" ).read( ) )
import collections as COLLECTIONS
STACK= COLLECTIONS.deque( [ COLLECTIONS.deque( [ NAMESPACE( FIELDNAME= "ROOT", NODE= ROOT ) ] ) ] )
while True:
    while STACK and not STACK[ - 1 ]:
        STACK.pop( )
    if not STACK:
        break
    ENTRY= STACK[ - 1 ].popleft( )
    if isinstance( ENTRY.NODE, AST.Load ) or isinstance( ENTRY.NODE, AST.Store ):
        continue
    print( " "* len( STACK )+ ENTRY.FIELDNAME+ ": "+ ENTRY.NODE.__class__.__name__ )
    ENTRY_2= COLLECTIONS.deque( )
    for FIELDNAME, NODE in AST.iter_fields( ENTRY.NODE ):
        FIELDNAME= FIELDNAME.upper( )
        if isinstance( NODE, AST.AST ):
            ENTRY_2.append( NAMESPACE( FIELDNAME= FIELDNAME, NODE= NODE ) )
            continue
        if isinstance( NODE, list ):
            ENTRY_2.extend( NAMESPACE( FIELDNAME= FIELDNAME+ F"[ { Z } ]", NODE= NODE_0 ) for Z, NODE_0 in enumerate( NODE ) )
            continue
        print( " "* ( len( STACK )+ 1 )+ FIELDNAME+ ": "+ repr( NODE )[ : 40 ] )
    STACK.append( ENTRY_2 )