Asteria (Al2O3)

Missing AST features

Features

• Repr implementation to every node (uses astpretty if it is available, if not fall backs to the ast.dump)
• AST Comparisons with other nodes
• Custom initializer with finding default values according to ASDL spec
• Shortcuts for fix_missing_locations, compile (e.g ast.parse("2+2").compile())
• Unparsing shortcuts, ast.parse("2+2").to_source(). It uses astor if its available, if not it fallbacks to the ast.unparse interface.
• Parent/Child relationships to nodes
• Helpers functions for mutating tree (like add_global method to Module nodes which inserts given node at the top of body)
• Symbol table access with get_symbol_table method
• and many more...

Demo

>>> import ast
>>> import asteria
>>> ast.parse("2+2") == ast.parse("2+2")
True
>>> ast.parse("2+2").body[0].value
BinOp(
    left=Constant(value=2, kind=None),
    op=Add(),
    right=Constant(value=2, kind=None),
)
>>> ast.parse("print(2+2)").compile()
<code object <module> at 0x7f2602f21450, file "<ASTERIA>", line 1>
>>> eval(_)
4
>>> ast.parse("import asteria").to_source()
'import asteria'
>>> sample = ast.parse("2+2")
>>> sample.parentize()
>>> sample.body[0].value.left.parent
BinOp(
    left=Constant(value=2, kind=None),
    op=Add(),
    right=Constant(value=2, kind=None),
)
>>> sample.body[0].value.parent
Expr(
    value=BinOp(
        left=Constant(value=2, kind=None),
        op=Add(),
        right=Constant(value=2, kind=None),
    ),
)
>>> some_try = ast.parse("""\
... try:                
...     def x():        
...             print(1)
... finally: pass       
... """)
>>> some_try.parentize()
>>> some_try.body[0].body[0].body[0].value
Call(
    func=Name(id='print', ctx=Load()),
    args=[Constant(value=1, kind=None)],
    keywords=[],
)
>>> len(tuple(some_try.body[0].body[0].body[0].value.until_parented_by(ast.Try)))
3
>>> some_try.add_global(ast.parse("print('lol')").body[0])
>>> print(some_try.to_source())
print('lol')
try:

    def x():
        print(1)
finally:
    pass