Move required packages to extras and guess default driver

.github/workflows/actions.yml

@@ -41,7 +41,7 @@ jobs:
           pip install --upgrade pip setuptools wheel
           pip install flake8 flake8-print coverage
           python testsrequire.py
-          python setup.py develop
+          pip install -e .[http,native,async]
           # Limit each test time execution.
           pip install pytest-timeout
       - name: Run flake8

clickhouse_sqlalchemy/drivers/__init__.py

@@ -1,4 +1,26 @@
 from . import base
-from .http import base as http_driver
 
-base.dialect = http_driver.dialect
+try:
+    from .native import base as native_driver
+
+    base.dialect = native_driver.dialect
+except ImportError:
+    pass
+
+if not hasattr(base, 'dialect'):
+    try:
+        from .http import base as http_driver
+
+        base.dialect = http_driver.dialect
+    except ImportError:
+        pass
+
+if not hasattr(base, 'dialect'):
+    try:
+        from .asynch import base as asynch_driver
+        base.dialect = asynch_driver.dialect
+    except ImportError:
+        pass
+
+if not hasattr(base, 'dialect'):
+    raise RuntimeError('Unable to detect default dialect. Please install one.')

clickhouse_sqlalchemy/drivers/default.py

@@ -0,0 +1,30 @@
+
+DefaultDialect = None
+
+try:
+    from .native import base as native_driver
+
+    DefaultDialect = native_driver.dialect
+except ImportError:
+    pass
+
+if DefaultDialect is None:
+    try:
+        from .http import base as http_driver
+
+        DefaultDialect = http_driver.dialect
+    except ImportError:
+        pass
+
+if DefaultDialect is None:
+    try:
+        from .asynch import base as asynch_driver
+
+        DefaultDialect = asynch_driver.dialect
+    except ImportError:
+        pass
+
+if DefaultDialect is None:
+    raise RuntimeError('Unable to detect default dialect. Please install one.')
+
+dialect = DefaultDialect

setup.py

@@ -29,7 +29,7 @@ def read_version():
     'clickhouse{}=clickhouse_sqlalchemy.drivers.{}'.format(driver, d_path)
 
     for driver, d_path in [
-        ('', 'http.base:ClickHouseDialect_http'),
+        ('', 'default:DefaultDialect'),
         ('.http', 'http.base:ClickHouseDialect_http'),
         ('.native', 'native.base:ClickHouseDialect_native'),
         ('.asynch', 'asynch.base:ClickHouseDialect_asynch'),
@@ -97,10 +97,12 @@ def read_version():
     python_requires='>=3.7, <4',
     install_requires=[
         'sqlalchemy>=2.0.0,<2.1.0',
-        'requests',
-        'clickhouse-driver>=0.1.2',
-        'asynch>=0.2.2,<=0.2.4',
     ],
+    extras_require={
+        'http': ['requests'],
+        'native': ['clickhouse-driver>=0.1.2'],
+        'async': ['asynch>=0.2.2,<=0.2.4']
+    },
     # Registering `clickhouse` as dialect.
     entry_points={
         'sqlalchemy.dialects': dialects

testsrequire.py

@@ -5,7 +5,6 @@
     'sqlalchemy>=2.0.0,<2.1.0',
     'greenlet>=2.0.1',
     'alembic',
-    'requests',
     'responses',
     'parameterized'
 ]