Create delegated pyi

Setup

Basics

imp_mod

def imp_mod(
    module_path, package:NoneType=None
):

Import dynamically the module referenced in fn

fn = Path('test_py2pyi.py')

mod = imp_mod(fn)
a = mod.A()
a.h()

tree = _get_tree(mod)

AST.repr

def __repr__():

# for o in enumerate(tree.body): print(o)

node = tree.body[4]
node

def f(a: int, b: str='a') -> str:
    """I am f"""
    return 1

isinstance(node, functypes)

True

source

has_deco

def has_deco(
    node:Union[ast.FunctionDef, ast.AsyncFunctionDef], name:str
)->bool:

Check if a function node node has a decorator named name

nm = 'delegates'
has_deco(node, nm)

False

node = tree.body[5]
node

@delegates(f)
def g(c, d: X, **kwargs) -> str:
    """I am g"""
    return 2

has_deco(node, nm)

True

Function processing

def _proc_body   (node, mod): print('_proc_body', type(node))
def _proc_func   (node, mod): print('_proc_func', type(node))
def _proc_class  (node, mod): print('_proc_class', type(node))
def _proc_patched(node, mod): print('_proc_patched', type(node))

parent_node = copy.deepcopy(tree.body[7])
patched_node = copy.deepcopy(tree.body[10])
test_is(has_deco(patched_node, "patch"), True)
test_eq(str(patched_node.args.args[0].annotation), parent_node.name)

_clean_patched_node(patched_node)
test_is(has_deco(patched_node, "patch"), False)
test_eq(patched_node.args.args[0].annotation, None)

empty_cls1, empty_cls2, empty_cls3 = ast.parse('''
class A: 
    """An empty class."""
class B: 
    pass
class C: 
    ...
''').body

test_is(_is_empty_class(empty_cls1), True)
test_is(_is_empty_class(empty_cls2), True)
test_is(_is_empty_class(empty_cls3), True)

non_empty_cls, empty_func = ast.parse('''
class A: 
    a = 1
def f():
    ...
''').body
test_is(_is_empty_class(non_empty_cls), False)
test_is(_is_empty_class(empty_func), False)

DeprecationWarning: ast.Ellipsis is deprecated and will be removed in Python 3.14; use ast.Constant instead
  if isinstance(child, ast.Expr) and isinstance(child.value, (ast.Ellipsis, ast.Str)): return True
<ipython-input-1-9bb9d38d0e66>:7: DeprecationWarning: ast.Str is deprecated and will be removed in Python 3.14; use ast.Constant instead
  if isinstance(child, ast.Expr) and isinstance(child.value, (ast.Ellipsis, ast.Str)): return True

# we could have reused `parent_node` and `patched_node` from the previous cells.
# copying them here allows us to run this cell multiple times which makes it a little easier to write tests.

parent_node = copy.deepcopy(tree.body[7])
patched_node = copy.deepcopy(tree.body[11])
test_eq(len(parent_node.body),1)
_add_patched_node_to_parent(patched_node, parent_node)
test_eq(len(parent_node.body),2)
test_eq(parent_node.body[-1], patched_node)

# patched node replaces an existing class method (A.h)
patched_h_node = ast.parse("""
@patch
def h(self: A, *args, **kwargs):
    ...
""", mode='single').body[0]

_add_patched_node_to_parent(patched_h_node, parent_node)
test_eq(len(parent_node.body), 2)
test_eq(parent_node.body[0], patched_h_node)

# patched node is added to an empty class
empty_cls, patched_node = ast.parse('''
class Z: 
    """An empty class."""

@patch
def a(self: Z, *args, **kwargs):
    ...
''').body

test_eq(len(empty_cls.body), 1)
test_ne(empty_cls.body[0], patched_node)
_add_patched_node_to_parent(patched_node, empty_cls)
test_eq(len(empty_cls.body), 1)
test_eq(empty_cls.body[0], patched_node)

DeprecationWarning: ast.Ellipsis is deprecated and will be removed in Python 3.14; use ast.Constant instead
  if isinstance(child, ast.Expr) and isinstance(child.value, (ast.Ellipsis, ast.Str)): return True
<ipython-input-1-9bb9d38d0e66>:7: DeprecationWarning: ast.Str is deprecated and will be removed in Python 3.14; use ast.Constant instead
  if isinstance(child, ast.Expr) and isinstance(child.value, (ast.Ellipsis, ast.Str)): return True

raw_tree = _get_tree(mod)
processed_tree = _proc_mod(mod)
n_raw_tree_nodes = len(raw_tree.body)
# mod contains 3 patch methods so our processed_tree should have 3 less nodes 
test_eq(len(processed_tree.body), n_raw_tree_nodes-3)

_proc_class <class 'ast.ClassDef'>
_proc_body <class 'ast.FunctionDef'>
_proc_func <class 'ast.FunctionDef'>
_proc_body <class 'ast.FunctionDef'>
_proc_class <class 'ast.ClassDef'>
_proc_class <class 'ast.ClassDef'>
_proc_patched <class 'ast.FunctionDef'>
_proc_patched <class 'ast.FunctionDef'>
_proc_body <class 'ast.FunctionDef'>

DeprecationWarning: ast.Ellipsis is deprecated and will be removed in Python 3.14; use ast.Constant instead
  if isinstance(child, ast.Expr) and isinstance(child.value, (ast.Ellipsis, ast.Str)): return True

_proc_mod(mod);

DeprecationWarning: ast.Ellipsis is deprecated and will be removed in Python 3.14; use ast.Constant instead
  if isinstance(child, ast.Expr) and isinstance(child.value, (ast.Ellipsis, ast.Str)): return True

node.name

'g'

sym = getattr(mod, node.name)
sym

<function test_py2pyi.g(c, d: test_py2pyi.X, *, b: str = 'a') -> str>

sig = signature(sym)
print(sig)

(c, d: test_py2pyi.X, *, b: str = 'a') -> str

source

sig2str

def sig2str(
    sig
):

source

ast_args

def ast_args(
    func
):

newargs = ast_args(sym)
newargs

c, d: test_py2pyi.X, *, b: str='a'

node.args

c, d: X, **kwargs

node.args = newargs
node

@delegates(f)
def g(c, d: test_py2pyi.X, *, b: str='a') -> str:
    """I am g"""
    return 2

_body_ellip(node)
node

DeprecationWarning: ast.Str is deprecated and will be removed in Python 3.14; use ast.Constant instead
  stidx = 1 if isinstance(n.body[0], ast.Expr) and isinstance(n.body[0].value, ast.Str) else 0

@delegates(f)
def g(c, d: test_py2pyi.X, *, b: str='a') -> str:
    """I am g"""
    ...

tree = _get_tree(mod)
node = tree.body[5]
node

@delegates(f)
def g(c, d: X, **kwargs) -> str:
    """I am g"""
    return 2

_update_func(node, sym)
node

DeprecationWarning: ast.Str is deprecated and will be removed in Python 3.14; use ast.Constant instead
  stidx = 1 if isinstance(n.body[0], ast.Expr) and isinstance(n.body[0].value, ast.Str) else 0

def g(c, d: X, *, b: str='a') -> str:
    """I am g"""
    ...

tree = _proc_mod(mod)
tree.body[5]

_proc_class <class 'ast.ClassDef'>
_proc_class <class 'ast.ClassDef'>
_proc_class <class 'ast.ClassDef'>
_proc_patched <class 'ast.FunctionDef'>
_proc_patched <class 'ast.FunctionDef'>

DeprecationWarning: ast.Str is deprecated and will be removed in Python 3.14; use ast.Constant instead
  stidx = 1 if isinstance(n.body[0], ast.Expr) and isinstance(n.body[0].value, ast.Str) else 0
<ipython-input-1-9bb9d38d0e66>:7: DeprecationWarning: ast.Ellipsis is deprecated and will be removed in Python 3.14; use ast.Constant instead
  if isinstance(child, ast.Expr) and isinstance(child.value, (ast.Ellipsis, ast.Str)): return True

def g(c, d: X, *, b: str='a') -> str:
    """I am g"""
    ...

Patch

tree = _get_tree(mod)
node = tree.body[9]
node

@patch
@delegates(j)
def k(self: (A, B), b: bool=False, **kwargs):
    return 1

ann = node.args.args[0].annotation

if hasattr(ann, 'elts'): ann = ann.elts[0]

nm = ann.id
nm

'A'

cls = getattr(mod, nm)
sym = getattr(cls, node.name)

sig2str(signature(sym))

"(self: (test_py2pyi.A, test_py2pyi.B), b: bool = False, *, d: str = 'a')"

_update_func(node, sym)

node

@patch
def k(self: (A, B), b: bool=False, *, d: str='a'):
    ...

tree = _get_tree(mod)
tree.body[9]

@patch
@delegates(j)
def k(self: (A, B), b: bool=False, **kwargs):
    return 1

Class and file

tree = _get_tree(mod)
node = tree.body[7]
node

class A:

    @delegates(j)
    def h(self, b: bool=False, **kwargs):
        a = 1
        return a

node.body

[@delegates(j)
 def h(self, b: bool=False, **kwargs):
     a = 1
     return a]

tree = _proc_mod(mod)
tree.body[7]

DeprecationWarning: ast.Str is deprecated and will be removed in Python 3.14; use ast.Constant instead
  stidx = 1 if isinstance(n.body[0], ast.Expr) and isinstance(n.body[0].value, ast.Str) else 0
<ipython-input-1-9bb9d38d0e66>:7: DeprecationWarning: ast.Ellipsis is deprecated and will be removed in Python 3.14; use ast.Constant instead
  if isinstance(child, ast.Expr) and isinstance(child.value, (ast.Ellipsis, ast.Str)): return True

class A:

    def h(self, b: bool=False, *, d: str='a'):
        ...

    def k(self, b: bool=False, *, d: str='a'):
        ...

    def m(self, b: bool=False, *, d: str='a'):
        ...

    def n(self, b: bool=False, **kwargs):
        """No delegates here mmm'k?"""
        ...

source

create_pyi

def create_pyi(
    fn, package:NoneType=None
):

Convert fname.py to fname.pyi by removing function bodies and expanding delegates kwargs

create_pyi(fn)

DeprecationWarning: ast.Str is deprecated and will be removed in Python 3.14; use ast.Constant instead
  stidx = 1 if isinstance(n.body[0], ast.Expr) and isinstance(n.body[0].value, ast.Str) else 0
<ipython-input-1-9bb9d38d0e66>:7: DeprecationWarning: ast.Ellipsis is deprecated and will be removed in Python 3.14; use ast.Constant instead
  if isinstance(child, ast.Expr) and isinstance(child.value, (ast.Ellipsis, ast.Str)): return True

# fn = Path('/Users/jhoward/git/fastcore/fastcore/docments.py')
# create_pyi(fn, 'fastcore')

Script

source

py2pyi

def py2pyi(
    fname:str, # The file name to convert
    package:str=None, # The parent package
):

Convert fname.py to fname.pyi by removing function bodies and expanding delegates kwargs

source

replace_wildcards

def replace_wildcards(
    path:str, # Path to the Python file to process
):

Expand wildcard imports in the specified Python file.

Setup

Basics

imp_mod

AST.__repr__

has_deco

Function processing

sig2str

ast_args

Patch

Class and file

create_pyi

Script

py2pyi

replace_wildcards

AST.repr