Restore Python 3.9 compatibility

Author: chad-earthscope

pyproject.toml

@@ -156,6 +156,8 @@ ignore = [
     "E501",  # line too long, handled by ruff format
     "B008",  # do not perform function calls in argument defaults
     "C901",  # too complex
+    "UP007", # Use X | Y for type annotations (keep Optional[X] for Python 3.9 compatibility)
+    "UP045", # Use X | Y for type annotations (keep Optional[X] for Python 3.9 compatibility)
 ]
 
 [tool.ruff.lint.per-file-ignores]

src/pymseed/__init__.py

@@ -1,23 +1,21 @@
 from .__version__ import __version__
 from .clib import clibmseed, ffi
-
 from .definitions import (
     DataEncoding,
-    TimeFormat,
     SubSecond,
+    TimeFormat,
 )
-
 from .exceptions import MiniSEEDError
 from .msrecord import MS3Record
-from .msrecord_reader import MS3RecordReader
 from .msrecord_buffer_reader import MS3RecordBufferReader
+from .msrecord_reader import MS3RecordReader
 from .mstracelist import MS3TraceList
 from .util import (
-    nstime2timestr,
-    timestr2nstime,
-    sourceid2nslc,
     nslc2sourceid,
+    nstime2timestr,
     sample_time,
+    sourceid2nslc,
+    timestr2nstime,
 )
 
 libmseed_version = ffi.string(clibmseed.LIBMSEED_VERSION).decode('utf-8')

src/pymseed/clib.py

@@ -3,13 +3,13 @@
 
 """
 
-from typing import Optional, Any
-
+from typing import Any, Optional
 
 try:
     # This is the correct pattern: import the ffi and lib objects
     # directly FROM the compiled _libmseed_cffi module.
-    from ._libmseed_cffi import ffi, lib as clibmseed
+    from ._libmseed_cffi import ffi
+    from ._libmseed_cffi import lib as clibmseed  # noqa: F401
 
 except ImportError as exc:
     # The friendly error message is still a good idea.

src/pymseed/definitions.py

@@ -11,7 +11,7 @@
 try:
     from .clib import clibmseed
 except ImportError:
-    raise ImportError("CFFI interface not available. Please build the CFFI interface first.")
+    raise ImportError("CFFI interface not available. Please build the CFFI interface first.") from None
 
 
 class DataEncoding(IntEnum):

src/pymseed/exceptions.py

@@ -1,4 +1,5 @@
 from typing import Optional
+
 from .util import error_string
 
 

src/pymseed/msrecord.py

@@ -8,8 +8,8 @@
 from contextlib import contextmanager
 from typing import Any, Callable, Optional, Union
 
-from .clib import clibmseed, ffi, cdata_to_string
-from .definitions import DataEncoding, SubSecond, TimeFormat
+from .clib import cdata_to_string, clibmseed, ffi
+from .definitions import SubSecond, TimeFormat
 from .exceptions import MiniSEEDError
 from .util import encoding_string, nstime2timestr, timestr2nstime
 
@@ -42,6 +42,7 @@ class MS3Record:
             FDSN:IU_COLA_00_L_H_1: 135 samples
 
         Creating and writing records:
+            >>> from pymseed import MS3Record, DataEncoding
             >>> record = MS3Record()
             >>> record.sourceid = "FDSN:NET_STA_LOC_B_S_s"
             >>> record.starttime_str = "2024-01-01T00:00:00Z"
@@ -454,7 +455,7 @@ def encoding(self) -> int:
             int: Encoding format code
 
         Examples:
-            >>> from pymseed import MS3Record
+            >>> from pymseed import MS3Record, DataEncoding
             >>> record = MS3Record()
             >>> record.encoding = DataEncoding.STEIM2
             >>> record.encoding = DataEncoding.FLOAT32
@@ -780,7 +781,7 @@ def with_datasamples(self, data_samples: Sequence[Any], sample_type: str):
         Examples:
             Setting data samples for packing:
 
-            >>> from pymseed import MS3Record
+            >>> from pymseed import MS3Record, DataEncoding
             >>> record = MS3Record()
             >>> record.sourceid = "FDSN:XX_TEST__L_S_X"
             >>> record.reclen = 512
@@ -961,6 +962,7 @@ def pack(
             ValueError: If sample_type is invalid or data format is incompatible
 
         Examples:
+            >>> from pymseed import MS3Record, DataEncoding
             >>> # Write to file
             >>> def file_handler(record_bytes, file_handle):
             ...     file_handle.write(record_bytes)

src/pymseed/mstracelist.py

@@ -6,13 +6,13 @@
 from __future__ import annotations
 
 from collections.abc import Sequence
-from typing import Any, Optional, Callable
+from typing import Any, Callable, Optional
 
-from .clib import clibmseed, ffi, cdata_to_string
+from .clib import cdata_to_string, clibmseed, ffi
 from .definitions import DataEncoding, SubSecond, TimeFormat
 from .exceptions import MiniSEEDError
 from .msrecord import MS3Record
-from .util import nstime2timestr, encoding_sizetype
+from .util import encoding_sizetype, nstime2timestr
 
 
 class MS3RecordPtr:
@@ -100,7 +100,8 @@ def indent_repr(thing):
                 indent_repr(self[-1]),
             ]
 
-        return f"MS3RecordList(recordcnt: {len(self)}\n{'\n'.join(formatted_lines)}\n)"
+        newline = "\n"
+        return f"MS3RecordList(recordcnt: {len(self)}\n{newline.join(formatted_lines)}\n)"
 
     def __str__(self) -> str:
         def indent_str(thing):
@@ -119,7 +120,8 @@ def indent_str(thing):
                 indent_str(self[-1]),
             ]
 
-        return f"Record list with {len(self)} records\n{'\n'.join(formatted_lines)}"
+        newline = "\n"
+        return f"Record list with {len(self)} records\n{newline.join(formatted_lines)}"
 
     def __len__(self) -> int:
         """Return number of records"""
@@ -567,7 +569,7 @@ def unpack_recordlist(self, buffer: Any = None, verbose: int = 0) -> int:
                         else len(buffer)
                     )
                 except (TypeError, AttributeError):
-                    raise ValueError("Buffer must support the buffer protocol")
+                    raise ValueError("Buffer must support the buffer protocol") from None
 
         status = clibmseed.mstl3_unpack_recordlist(
             self._parent_id,
@@ -582,7 +584,7 @@ def unpack_recordlist(self, buffer: Any = None, verbose: int = 0) -> int:
         else:
             return status
 
-    def has_same_data(self, other: "MS3TraceSeg") -> bool:
+    def has_same_data(self, other: MS3TraceSeg) -> bool:
         """Compare trace segments for equivalent data
 
         Args:
@@ -637,13 +639,14 @@ def indent_repr(thing):
                 indent_repr(self[-1]),
             ]
 
+        newline = "\n"
         return (
             f"MS3TraceID(sourceid: {self.sourceid}\n"
             f"         pubversion: {self.pubversion}\n"
             f"         earliest: {self.earliest_str(timeformat=TimeFormat.ISOMONTHDAY_DOY_Z)}\n"
             f"         latest: {self.latest_str(timeformat=TimeFormat.ISOMONTHDAY_DOY_Z)}\n"
             f"         numsegments: {len(self)}\n"
-            f"{'\n'.join(formatted_lines)}"
+            f"{newline.join(formatted_lines)}"
             "\n)"
         )
 
@@ -867,10 +870,8 @@ def indent_repr(thing):
                 indent_repr(self[-1]),
             ]
 
-        return (f"MS3TraceList(numtraceids: {len(self)}\n"
-                f"{'\n'.join(formatted_lines)}\n"
-                ")"
-        )
+        newline = "\n"
+        return f"MS3TraceList(numtraceids: {len(self)}\n{newline.join(formatted_lines)}\n)"
 
     def __str__(self) -> str:
         def indent_str(thing):
@@ -889,7 +890,8 @@ def indent_str(thing):
                 indent_str(self[-1]),
             ]
 
-        return f"Trace list with {len(self)} trace IDs\n{'\n'.join(formatted_lines)}\n"
+        newline = "\n"
+        return f"Trace list with {len(self)} trace IDs\n{newline.join(formatted_lines)}\n"
 
     def __len__(self) -> int:
         """Return number of trace IDs in the list"""

src/pymseed/util.py

@@ -3,7 +3,8 @@
 
 """
 
-from typing import Optional, Union
+from typing import Optional
+
 from .clib import cdata_to_string, clibmseed, ffi
 from .definitions import SubSecond, TimeFormat