__init__.py.j2

{% extends '_base.py.j2' %}
{% block content %}
{% if opts.lazy_import -%} {# lazy import #}
import importlib
import sys


if sys.version_info < (3, 7):
    raise ImportError('This module requires Python 3.7 or later.')


_lazy_type_to_package_map = {
    # Message types
{%- for message in api.top_level_messages.values() %}
    '{{ message.name }}': '{{ message.ident.package|join('.') }}.types.{{ message.ident.module }}',
{%- endfor %}
  
    # Enum types
{%- for enum in api.top_level_enums.values() %}
    '{{ enum.name }}': '{{ enum.ident.package|join('.') }}.types.{{enum.ident.module }}',
{%- endfor %}
  
    # Client classes and transports  
{%- for service in api.services.values() %}
    '{{ service.client_name }}': '{{ service.meta.address.package|join('.') }}.services.{{ service.meta.address.module }}',
    '{{ service.transport_name }}': '{{ service.meta.address.package|join('.') }}.services.{{ service.meta.address.module }}.transports',
    '{{ service.grpc_transport_name }}': '{{ service.meta.address.package|join('.') }}.services.{{ service.meta.address.module }}.transports',
{%- endfor %}
}

class _EnumGetter:
    def __getattr__(self, name):
        return __getattr__(name)


@property
def _enum_getter(self):
    """Getter utility that attaches all Enum classes to a given object."""
    return _EnumGetter()


# Background on how this behaves: https://www.python.org/dev/peps/pep-0562/
def __getattr__(name):  # Requires Python >= 3.7
    if name == '__all__':
        all_names = globals()['__all__'] = sorted(_lazy_type_to_package_map)
        return all_names
    elif name in _lazy_type_to_package_map:
        module = importlib.import_module(f'{_lazy_type_to_package_map[name]}')
        klass = getattr(module, name)
        if name.endswith('ServiceClient'):
            klass = type(name, (klass,), dict(enums=_enum_getter))
        globals()[name] = klass
        return klass
    else:
        raise AttributeError(f'unknown type {name!r}.')


def __dir__():
    return globals().get('__all__') or __getattr__('__all__')
{% else -%}                {# do not use lazy import #}
{#  Import subpackages. -#}
{% filter sort_lines -%}
{% for subpackage in api.subpackages.keys() -%}
from {% if api.naming.module_namespace %}{{ api.naming.module_namespace|join('.') }}.{% endif -%}
    {{ api.naming.versioned_module_name }} import {{ subpackage }}
{% endfor -%}

{#  Import services for this package. -#}
{% for service in api.services.values()|sort(attribute='name')
        if service.meta.address.subpackage == api.subpackage_view -%}
from {% if api.naming.module_namespace %}{{ api.naming.module_namespace|join('.') }}.{% endif -%}
    {{ api.naming.versioned_module_name }}.services.{{ service.name|snake_case }}.client import {{ service.client_name }}
{% endfor -%}

{#  Import messages and enums from each proto.
    It is safe to import all of the messages into the same namespace here,
    because protocol buffers itself enforces selector uniqueness within
    a proto package.
-#}
{#  Import messages from each proto.
    It is safe to import all of the messages into the same namespace here,
    because protocol buffers itself enforces selector uniqueness within
    a proto package.
  -#}
{% for proto in api.protos.values()|sort(attribute='module_name')
        if proto.meta.address.subpackage == api.subpackage_view -%}
  {% for message in proto.messages.values()|sort(attribute='name') -%}
from {% if api.naming.module_namespace %}{{ api.naming.module_namespace|join('.') }}.{% endif -%}
    {{ api.naming.versioned_module_name }}.types.{{ proto.module_name }} import {{ message.name }}
{% endfor -%}
{% for enum in proto.enums.values()|sort(attribute='name') -%}
from {% if api.naming.module_namespace %}{{ api.naming.module_namespace|join('.') }}.{% endif -%}
    {{ api.naming.versioned_module_name }}.types.{{ proto.module_name }} import {{ enum.name }}
{% endfor %}{% endfor -%}
{% endfilter %}
{#  Define __all__.
    This requires the full set of imported names, so we iterate over
    them again.
-#}
__all__ = (
{%- filter indent %}
{% filter sort_lines -%}
{% for subpackage in api.subpackages.keys() -%}
'{{ subpackage }}',
{% endfor -%}
{% for service in api.services.values()|sort(attribute='name')
   if service.meta.address.subpackage == api.subpackage_view -%}
'{{ service.client_name }}',
{% endfor -%}
{% for proto in api.protos.values()|sort(attribute='module_name')
   if proto.meta.address.subpackage == api.subpackage_view -%}
{% for message in proto.messages.values()|sort(attribute='name') -%}
'{{ message.name }}',
{% endfor -%}
{% for enum in proto.enums.values()|sort(attribute='name')
   if proto.meta.address.subpackage == api.subpackage_view -%}
'{{ enum.name }}',
{% endfor -%}{% endfor -%}
{% endfilter -%}
{% endfilter -%}
)
{% endif -%} {# lazy import #}
{% endblock %}