refactor: Drop support for Python 3.7

Backport from the V1 branch to maybe release this earlier?

.github/ISSUE_TEMPLATE/bug.yml

@@ -32,7 +32,6 @@ body:
       description: Version of Python you are using
       options:
         - "3.6 (deprecated)"
-        - "3.7"
         - "3.8"
         - "3.9"
         - "3.10"
@@ -76,6 +75,6 @@ body:
     attributes:
       label: Code
       description: Paste the failing code and/or traceback, if applicable
-      render: python
+      render: Python
     validations:
       required: false

.github/workflows/test.yml

@@ -47,7 +47,7 @@ jobs:
       matrix:
         session: [tests]
         os: ["ubuntu-latest", "macos-latest", "windows-latest"]
-        python-version: ["3.7", "3.8", "3.9", "3.10", "3.11", "3.12"]
+        python-version: ["3.8", "3.9", "3.10", "3.11", "3.12"]
         sqlalchemy: ["2"]
         include:
         - { session: tests,   python-version: "3.11", os: "ubuntu-latest", sqlalchemy: "1" }

noxfile.py

@@ -28,7 +28,7 @@
 COOKIECUTTER_REPLAY_FILES = list(Path("./e2e-tests/cookiecutters").glob("*.json"))
 
 package = "singer_sdk"
-python_versions = ["3.12", "3.11", "3.10", "3.9", "3.8", "3.7"]
+python_versions = ["3.12", "3.11", "3.10", "3.9", "3.8"]
 main_python_version = "3.11"
 locations = "singer_sdk", "tests", "noxfile.py", "docs/conf.py"
 nox.options.sessions = (

pyproject.toml

@@ -19,7 +19,6 @@ classifiers = [
     "Intended Audience :: Developers",
     "License :: OSI Approved :: Apache Software License",
     "Operating System :: OS Independent",
-    "Programming Language :: Python :: 3.7",
     "Programming Language :: Python :: 3.8",
     "Programming Language :: Python :: 3.9",
     "Programming Language :: Python :: 3.10",
@@ -39,7 +38,7 @@ license = "Apache-2.0"
 "Youtube" = "https://www.youtube.com/meltano"
 
 [tool.poetry.dependencies]
-python = ">=3.7.1"
+python = ">=3.8"
 backoff = { version = ">=2.0.0", python = "<4" }
 backports-datetime-fromisoformat = { version = ">=2.0.1", python = "<3.11" }
 click = "~=8.0"
@@ -50,16 +49,10 @@ importlib-resources = {version = ">=5.12.0", python = "<3.9"}
 inflection = ">=0.5.1"
 joblib = ">=1.0.1"
 jsonpath-ng = ">=1.5.3"
-jsonschema = [
-    { version = ">=4.16.0,<4.18", python = "<3.8" },
-    { version = ">=4.16.0", python = ">=3.8" },
-]
+jsonschema = ">=4.16.0"
 memoization = { version = ">=0.3.2,<0.5.0", python = "<4" }
 packaging = ">=23.1"
-pendulum = [
-    { version = ">=2.1.0,<3", python = "<3.8" },
-    { version = ">=2.1.0,<4", python = ">=3.8" },
-]
+pendulum = ">=2.1.0,<4"
 PyJWT = "~=2.4"
 python-dateutil = ">=2.8.2"
 python-dotenv = ">=0.20"
@@ -80,23 +73,19 @@ furo = {version = ">=2022.12.7", optional = true}
 sphinx-copybutton = {version = ">=0.3.1", optional = true}
 myst-parser = {version = ">=1", optional = true}
 sphinx-autobuild = {version = ">=2021.3.14", optional = true}
-sphinx-inline-tabs = {version = ">=2023.4.21", optional = true, markers = "python_version >= \"3.8\""}
-sphinx-notfound-page = {version = ">=1.0.0", optional = true, python = ">=3.8"}
+sphinx-inline-tabs = {version = ">=2023.4.21", optional = true }
+sphinx-notfound-page = {version = ">=1.0.0", optional = true }
 sphinx-reredirects = {version = ">=0.1.1", optional = true}
 
 # File storage dependencies installed as optional 'filesystem' extras
 fs-s3fs = {version = ">=1.1.1", optional = true}
 
 # Parquet file dependencies installed as optional 'parquet' extras
 numpy = [
-    { version = "<1.22", python = "<3.8", optional = true },
     { version = ">=1.22,<1.25", python = ">=3.8,<3.9", optional = true },
     { version = ">=1.22", python = ">=3.9", optional = true },
 ]
-pyarrow = [
-    { version = ">=11,<13", python = "<3.8", optional = true },
-    { version = ">=13", python = ">=3.8", optional = true }
-]
+pyarrow = { version = ">=13", optional = true }
 
 # Testing dependencies installed as optional 'testing' extras
 pytest = {version=">=7.2.1", optional = true}
@@ -121,31 +110,18 @@ testing = [
 parquet = ["numpy", "pyarrow"]
 
 [tool.poetry.group.dev.dependencies]
-coverage = [
-    {extras = ["toml"], version = ">=7.2,<7.3", python = "<3.8"},
-    {extras = ["toml"], version = ">=7.2", python = ">=3.8,<3.12"},
-    {extras = ["toml"], version = ">=7.4", python = ">=3.12"},
-]
+coverage = {extras = ["toml"], version = ">=7.4"}
 
 # TODO: Remove the Python 3.12 marker when DuckDB supports it
 duckdb = { version = ">=0.8.0", python = "<3.12" }
 duckdb-engine = { version = ">=0.9.4", python = "<3.12" }
 
-mypy = [
-    { version = ">=1.0,<1.5", python = "<3.8" },
-    { version = ">=1.0", python = ">=3.8" },
-]
+mypy = ">=1.0"
 pytest-benchmark = ">=4.0.0"
 pytest-snapshot = ">=0.9.0"
 requests-mock = ">=1.10.0"
-time-machine = [
-    { version = ">=2.10.0,<2.11", python = "<3.8" },
-    { version = ">=2.10.0", python = ">=3.8" },
-]
-types-jsonschema = [
-    { version = ">=4.17.0.6,<4.18", python = "<3.8" },
-    { version = ">=4.17.0.6", python = ">=3.8" },
-]
+time-machine = ">=2.10.0"
+types-jsonschema = ">=4.17.0.6"
 types-python-dateutil = ">=2.8.19"
 types-pytz = ">=2022.7.1.2"
 types-requests = ">=2.28.11"
@@ -247,7 +223,7 @@ parquet = "singer_sdk.contrib.batch_encoder_parquet:ParquetBatcher"
 [tool.ruff]
 line-length = 88
 src = ["samples", "singer_sdk", "tests"]
-target-version = "py37"
+target-version = "py38"
 
 [tool.ruff.format]
 docstring-code-format = true

singer_sdk/connectors/sql.py

@@ -359,7 +359,7 @@ def quote(self, name: str) -> str:
             ],
         )
 
-    @lru_cache()  # noqa: B019
+    @lru_cache  # noqa: B019
     def _warn_no_view_detection(self) -> None:
         """Print a warning, but only the first time."""
         self.logger.warning(

singer_sdk/helpers/_compat.py

@@ -5,13 +5,6 @@
 import datetime
 import sys
 
-if sys.version_info < (3, 8):
-    import importlib_metadata as metadata
-    from typing_extensions import final
-else:
-    from importlib import metadata
-    from typing import final  # noqa: ICN003
-
 if sys.version_info < (3, 9):
     import importlib_resources
 else:
@@ -39,8 +32,6 @@
 time_fromisoformat = datetime.time.fromisoformat
 
 __all__ = [
-    "metadata",
-    "final",
     "entry_points",
     "datetime_fromisoformat",
     "date_fromisoformat",

singer_sdk/helpers/_state.py

@@ -127,8 +127,10 @@ def get_writeable_state_dict(
     if "partitions" not in stream_state:
         stream_state["partitions"] = []
     stream_state_partitions: list[dict] = stream_state["partitions"]
-    found = _find_in_partitions_list(stream_state_partitions, state_partition_context)
-    if found:
+    if found := _find_in_partitions_list(
+        stream_state_partitions,
+        state_partition_context,
+    ):
         return found
 
     return _create_in_partitions_list(stream_state_partitions, state_partition_context)

singer_sdk/helpers/_typing.py

@@ -326,7 +326,7 @@ def is_number_type(property_schema: dict) -> bool | None:
     return False
 
 
-@lru_cache()
+@lru_cache
 def _warn_unmapped_properties(
     stream_name: str,
     property_names: tuple[str],

singer_sdk/io_base.py

@@ -13,15 +13,14 @@
 from singer_sdk._singerlib.messages import Message, SingerMessageType
 from singer_sdk._singerlib.messages import format_message as singer_format_message
 from singer_sdk._singerlib.messages import write_message as singer_write_message
-from singer_sdk.helpers._compat import final
 
 logger = logging.getLogger(__name__)
 
 
 class SingerReader(metaclass=abc.ABCMeta):
     """Interface for all plugins reading Singer messages from stdin."""
 
-    @final
+    @t.final
     def listen(self, file_input: t.IO[str] | None = None) -> None:
         """Read from input until all messages are processed.
 

singer_sdk/pagination.py

@@ -2,18 +2,12 @@
 
 from __future__ import annotations
 
-import sys
 import typing as t
 from abc import ABCMeta, abstractmethod
 from urllib.parse import ParseResult, urlparse
 
 from singer_sdk.helpers.jsonpath import extract_jsonpath
 
-if sys.version_info >= (3, 8):
-    from typing import Protocol  # noqa: ICN003
-else:
-    from typing_extensions import Protocol
-
 if t.TYPE_CHECKING:
     from requests import Response
 
@@ -382,7 +376,7 @@ def get_next(self, response: Response) -> int | None:  # noqa: ARG002
         return self._value + self._page_size
 
 
-class LegacyPaginatedStreamProtocol(Protocol[TPageToken]):
+class LegacyPaginatedStreamProtocol(t.Protocol[TPageToken]):
     """Protocol for legacy paginated streams classes."""
 
     def get_next_page_token(

singer_sdk/plugin_base.py

@@ -8,6 +8,7 @@
 import sys
 import time
 import typing as t
+from importlib import metadata
 from pathlib import Path, PurePath
 from types import MappingProxyType
 
@@ -23,7 +24,6 @@
 )
 from singer_sdk.exceptions import ConfigValidationError
 from singer_sdk.helpers._classproperty import classproperty
-from singer_sdk.helpers._compat import metadata
 from singer_sdk.helpers._secrets import SecretString, is_common_secret_key
 from singer_sdk.helpers._util import read_json_file
 from singer_sdk.helpers.capabilities import (

singer_sdk/sinks/core.py

@@ -25,7 +25,6 @@
 from singer_sdk.helpers._compat import (
     date_fromisoformat,
     datetime_fromisoformat,
-    final,
     time_fromisoformat,
 )
 from singer_sdk.helpers._typing import (
@@ -144,7 +143,7 @@ def is_full(self) -> bool:
 
     # Tally methods
 
-    @final
+    @t.final
     def tally_record_read(self, count: int = 1) -> None:
         """Increment the records read tally.
 
@@ -156,7 +155,7 @@ def tally_record_read(self, count: int = 1) -> None:
         self._total_records_read += count
         self._batch_records_read += count
 
-    @final
+    @t.final
     def tally_record_written(self, count: int = 1) -> None:
         """Increment the records written tally.
 
@@ -169,7 +168,7 @@ def tally_record_written(self, count: int = 1) -> None:
         """
         self._total_records_written += count
 
-    @final
+    @t.final
     def tally_duplicate_merged(self, count: int = 1) -> None:
         """Increment the records merged tally.
 

singer_sdk/sinks/record.py

@@ -3,8 +3,8 @@
 from __future__ import annotations
 
 import abc
+import typing as t
 
-from singer_sdk.helpers._compat import final
 from singer_sdk.sinks.core import Sink
 
 
@@ -23,7 +23,7 @@ def _after_process_record(self, context: dict) -> None:  # noqa: ARG002
         """
         self.tally_record_written()
 
-    @final
+    @t.final
     def process_batch(self, context: dict) -> None:
         """Do nothing and return immediately.
 
@@ -35,7 +35,7 @@ def process_batch(self, context: dict) -> None:
             context: Stream partition or context dictionary.
         """
 
-    @final
+    @t.final
     def start_batch(self, context: dict) -> None:
         """Do nothing and return immediately.
 

singer_sdk/streams/core.py

@@ -29,7 +29,6 @@
     SDKBatchMessage,
 )
 from singer_sdk.helpers._catalog import pop_deselected_record_properties
-from singer_sdk.helpers._compat import final
 from singer_sdk.helpers._flattening import get_flattening_options
 from singer_sdk.helpers._state import (
     finalize_state_progress_markers,
@@ -303,7 +302,7 @@ def selected(self, value: bool | None) -> None:
         self.metadata.root.selected = value
         self._mask = self.metadata.resolve_selection()
 
-    @final
+    @t.final
     @property
     def has_selected_descendents(self) -> bool:
         """Check descendents.
@@ -316,7 +315,7 @@ def has_selected_descendents(self) -> bool:
             for child in self.child_streams or []
         )
 
-    @final
+    @t.final
     @property
     def descendent_streams(self) -> list[Stream]:
         """Get child streams.
@@ -1157,7 +1156,7 @@ def _sync_batches(
 
     # Public methods ("final", not recommended to be overridden)
 
-    @final
+    @t.final
     def sync(self, context: dict | None = None) -> None:
         """Sync this stream.
 

singer_sdk/streams/sql.py

@@ -4,6 +4,7 @@
 
 import abc
 import typing as t
+from functools import cached_property
 
 import sqlalchemy as sa
 
@@ -78,7 +79,7 @@ def metadata(self) -> MetadataMapping:
         """
         return self._singer_catalog_entry.metadata
 
-    @property  # TODO: Investigate @cached_property after py > 3.7
+    @cached_property
     def schema(self) -> dict:
         """Return metadata object (dict) as specified in the Singer spec.
 
@@ -87,13 +88,7 @@ def schema(self) -> dict:
         Returns:
             The schema object.
         """
-        if not self._cached_schema:
-            self._cached_schema = t.cast(
-                dict,
-                self._singer_catalog_entry.schema.to_dict(),
-            )
-
-        return self._cached_schema
+        return self._singer_catalog_entry.schema.to_dict()
 
     @property
     def tap_stream_id(self) -> str: