Script to generate pyi stubs.

tools/generate_pyi_stubs.py

@@ -0,0 +1,152 @@
+import re
+import os
+import sys
+import unreal_engine as ue
+
+
+# TODO: there are invalid names like 'IsInAir?' and 'EUserInterfaceActionType.None'
+VALID_NAME_PATTERN = re.compile('^[_a-zA-Z][_a-zA-Z0-9]*$')
+FILTERED_NAMES = {
+    '__new__', '__doc__',
+    '__str__', '__repr__', '__name__',
+    '__loader__', '__spec__', '__package__',
+    '__loader__', '__hash__', '__weakref__'
+}
+
+# This list is kinda reliable for descriptors implemented in C, it's ugly to get their types
+# https://docs.python.org/3/library/inspect.html#fetching-attributes-statically
+DESCRIPTORS = {'getset_descriptor', 'member_descriptor'}
+
+
+def is_valid_name(name):
+    return VALID_NAME_PATTERN.match(name) is not None and name not in FILTERED_NAMES
+
+
+def filter_names(names):
+    return (name for name in names if is_valid_name(name))
+
+
+def filter_attributes(attributes):
+    return {name: value for name, value in attributes.items() if is_valid_name(name)}
+
+
+def get_type_name(obj):
+    type_ = type(obj)
+    try:
+        return type_.__qualname__
+    except AttributeError:
+        return type_.__name__
+
+
+def is_class(t):
+    return isinstance(t, type)
+
+
+def is_callable(obj):
+    return hasattr(obj, '__call__')
+
+
+def write_function(file, name, indent):
+    file.write(indent)
+    # TODO: ideally methods functions should be handled differently, like have self
+    # but we don't know arguments and if it's staticmethod or classmethod anyway
+    file.write("def {}(*args, **kwargs) -> 'typing.Any': ...\n".format(name))
+
+
+def write_variable(file, name, value, indent):
+    type_name = get_type_name(value)
+    file.write(indent)
+
+    if isinstance(value, property) or value is None or type_name in DESCRIPTORS:
+        variable_type = 'typing.Any'
+    else:
+        variable_type = '{}'.format(type_name)
+
+    file.write(
+        "{}: '{}'\n".format(name, variable_type)
+    )
+
+
+def write_class(file, name, value, indent):
+    file.write(indent)
+    file.write("class {}:\n".format(name))
+    attributes = filter_attributes(vars(value))
+
+    if not attributes:
+        file.write(indent)
+        file.write("    pass\n")
+    else:
+        for attribute_name, attribute_value in attributes.items():
+            write_object(file, attribute_name, attribute_value, indent + '    ')
+
+    file.write('\n')
+    file.write('\n')
+
+
+def write_object(file, name, value, indent):
+    # TODO: https://github.com/20tab/UnrealEnginePython/issues/394 ESlateEnums contains invalid attributes
+    if not is_valid_name(name):
+        return
+
+    if is_class(value):
+        write_class(file, name, value, indent)
+    elif is_callable(value):
+        write_function(file, name, indent)
+    else:
+        write_variable(file, name, value, indent)
+
+
+def write_ue_classes(file, classes):
+    for class_ in classes:
+        file.write("class {}:\n".format(class_.get_name()))
+
+        attributes_count = 0
+
+        for property_ in filter_names(class_.properties()):
+            file.write("    ")
+            file.write("{}: 'typing.Any'\n".format(property_))
+            attributes_count += 1
+
+        for function_ in filter_names(class_.functions()):
+            file.write("    ")
+            file.write("def {}(*args, **kwargs) -> 'typing.Any': pass\n".format(function_))
+            attributes_count += 1
+
+        if attributes_count == 0:
+            file.write("    ")
+            file.write("pass\n")
+
+        file.write("\n")
+
+
+def generate_pyi_stubs(directory, include_reflection=False):
+    """
+    Generates pyi file. Note include_reflection has not been implemented yet.
+    """
+    # include_reflection is still WIP and bit unusable, because:
+    # * the result file is very large and PyCharm by default ignores such files
+    # * it contains some invalid identifiers ('IsInAir?')
+    if include_reflection:
+        raise NotImplementedError
+
+    package_dir = os.path.join(directory, 'unreal_engine')
+    os.mkdir(package_dir)
+
+    init_path = os.path.join(package_dir, '__init__.pyi')
+    with open(init_path, mode='w') as file:
+        file.write('import typing')
+        file.write('\n\n')
+
+        ue_public = vars(ue)
+        for name, value in filter_attributes(ue_public).items():
+            write_object(file, name, value, '')
+            file.write('\n')
+
+    if include_reflection:
+        classes_path = os.path.join(package_dir, 'classes.pyi')
+        with open(classes_path, mode='w') as file:
+            write_ue_classes(file, ue.all_classes())
+
+
+if __name__ == '__main__':
+    generate_pyi_stubs(sys.argv[1])