feat(api core): simplify from_rfc3339 methods (#9641)

Author: emar-kar

google/api_core/bidi.py

@@ -172,7 +172,9 @@ def __init__(self, access_limit, time_window):
 
         self._time_window = time_window
         self._access_limit = access_limit
-        self._past_entries = collections.deque(maxlen=access_limit)  # least recent first
+        self._past_entries = collections.deque(
+            maxlen=access_limit
+        )  # least recent first
         self._entry_lock = threading.Lock()
 
     def __enter__(self):
@@ -198,9 +200,7 @@ def __exit__(self, *_):
 
     def __repr__(self):
         return "{}(access_limit={}, time_window={})".format(
-            self.__class__.__name__,
-            self._access_limit,
-            repr(self._time_window),
+            self.__class__.__name__, self._access_limit, repr(self._time_window)
         )
 
 
@@ -423,7 +423,7 @@ def __init__(
 
         if throttle_reopen:
             self._reopen_throttle = _Throttle(
-                access_limit=5, time_window=datetime.timedelta(seconds=10),
+                access_limit=5, time_window=datetime.timedelta(seconds=10)
             )
         else:
             self._reopen_throttle = None

google/api_core/datetime_helpers.py

@@ -115,20 +115,10 @@ def from_iso8601_time(value):
 
 
 def from_rfc3339(value):
-    """Convert a microsecond-precision timestamp to datetime.
+    """Convert an RFC3339-format timestamp to a native datetime.
 
-    Args:
-        value (str): The RFC3339 string to convert.
-
-    Returns:
-        datetime.datetime: The datetime object equivalent to the timestamp in
-            UTC.
-    """
-    return datetime.datetime.strptime(value, _RFC3339_MICROS).replace(tzinfo=pytz.utc)
-
-
-def from_rfc3339_nanos(value):
-    """Convert a nanosecond-precision timestamp to a native datetime.
+    Supported formats include those without fractional seconds, or with
+    any fraction up to nanosecond precision.
 
     .. note::
         Python datetimes do not support nanosecond precision; this function
@@ -138,11 +128,11 @@ def from_rfc3339_nanos(value):
         value (str): The RFC3339 string to convert.
 
     Returns:
-        datetime.datetime: The datetime object equivalent to the timestamp in
-            UTC.
+        datetime.datetime: The datetime object equivalent to the timestamp
+        in UTC.
 
     Raises:
-        ValueError: If the timestamp does not match the RFC 3339
+        ValueError: If the timestamp does not match the RFC3339
             regular expression.
     """
     with_nanos = _RFC3339_NANOS.match(value)
@@ -169,6 +159,9 @@ def from_rfc3339_nanos(value):
     return bare_seconds.replace(microsecond=micros, tzinfo=pytz.utc)
 
 
+from_rfc3339_nanos = from_rfc3339  # from_rfc3339_nanos method was deprecated.
+
+
 def to_rfc3339(value, ignore_zone=True):
     """Convert a datetime to an RFC3339 timestamp string.
 
@@ -215,22 +208,22 @@ def nanosecond(self):
         return self._nanosecond
 
     def rfc3339(self):
-        """Return an RFC 3339-compliant timestamp.
+        """Return an RFC3339-compliant timestamp.
 
         Returns:
-            (str): Timestamp string according to RFC 3339 spec.
+            (str): Timestamp string according to RFC3339 spec.
         """
         if self._nanosecond == 0:
             return to_rfc3339(self)
-        nanos = str(self._nanosecond).rjust(9, '0').rstrip("0")
+        nanos = str(self._nanosecond).rjust(9, "0").rstrip("0")
         return "{}.{}Z".format(self.strftime(_RFC3339_NO_FRACTION), nanos)
 
     @classmethod
     def from_rfc3339(cls, stamp):
-        """Parse RFC 3339-compliant timestamp, preserving nanoseconds.
+        """Parse RFC3339-compliant timestamp, preserving nanoseconds.
 
         Args:
-            stamp (str): RFC 3339 stamp, with up to nanosecond precision
+            stamp (str): RFC3339 stamp, with up to nanosecond precision
 
         Returns:
             :class:`DatetimeWithNanoseconds`:
@@ -280,7 +273,7 @@ def timestamp_pb(self):
 
     @classmethod
     def from_timestamp_pb(cls, stamp):
-        """Parse RFC 3339-compliant timestamp, preserving nanoseconds.
+        """Parse RFC3339-compliant timestamp, preserving nanoseconds.
 
         Args:
             stamp (:class:`~google.protobuf.timestamp_pb2.Timestamp`): timestamp message

google/api_core/iam.py

@@ -34,11 +34,12 @@
 """
 
 import collections
+import warnings
+
 try:
     from collections import abc as collections_abc
 except ImportError:  # Python 2.7
     import collections as collections_abc
-import warnings
 
 # Generic IAM roles
 

google/api_core/protobuf_helpers.py

@@ -15,17 +15,19 @@
 """Helpers for :mod:`protobuf`."""
 
 import collections
-try:
-    from collections import abc as collections_abc
-except ImportError:  # Python 2.7
-    import collections as collections_abc
 import copy
 import inspect
 
 from google.protobuf import field_mask_pb2
 from google.protobuf import message
 from google.protobuf import wrappers_pb2
 
+try:
+    from collections import abc as collections_abc
+except ImportError:  # Python 2.7
+    import collections as collections_abc
+
+
 _SENTINEL = object()
 _WRAPPER_TYPES = (
     wrappers_pb2.BoolValue,

google/api_core/retry.py

@@ -237,7 +237,7 @@ def __init__(
         maximum=_DEFAULT_MAXIMUM_DELAY,
         multiplier=_DEFAULT_DELAY_MULTIPLIER,
         deadline=_DEFAULT_DEADLINE,
-        on_error=None
+        on_error=None,
     ):
         self._predicate = predicate
         self._initial = initial

tests/unit/test_datetime_helpers.py

@@ -82,18 +82,18 @@ def test_from_rfc3339():
     )
 
 
-def test_from_rfc3339_with_bad_tz():
-    value = "2009-12-17T12:44:32.123456BAD"
-
-    with pytest.raises(ValueError):
-        datetime_helpers.from_rfc3339(value)
-
+def test_from_rfc3339_nanos():
+    value = "2009-12-17T12:44:32.123456Z"
+    assert datetime_helpers.from_rfc3339_nanos(value) == datetime.datetime(
+        2009, 12, 17, 12, 44, 32, 123456, pytz.utc
+    )
 
-def test_from_rfc3339_with_nanos():
-    value = "2009-12-17T12:44:32.123456789Z"
 
-    with pytest.raises(ValueError):
-        datetime_helpers.from_rfc3339(value)
+def test_from_rfc3339_without_nanos():
+    value = "2009-12-17T12:44:32Z"
+    assert datetime_helpers.from_rfc3339(value) == datetime.datetime(
+        2009, 12, 17, 12, 44, 32, 0, pytz.utc
+    )
 
 
 def test_from_rfc3339_nanos_without_nanos():
@@ -103,11 +103,33 @@ def test_from_rfc3339_nanos_without_nanos():
     )
 
 
-def test_from_rfc3339_nanos_with_bad_tz():
-    value = "2009-12-17T12:44:32.123456789BAD"
+@pytest.mark.parametrize(
+    "truncated, micros",
+    [
+        ("12345678", 123456),
+        ("1234567", 123456),
+        ("123456", 123456),
+        ("12345", 123450),
+        ("1234", 123400),
+        ("123", 123000),
+        ("12", 120000),
+        ("1", 100000),
+    ],
+)
+def test_from_rfc3339_with_truncated_nanos(truncated, micros):
+    value = "2009-12-17T12:44:32.{}Z".format(truncated)
+    assert datetime_helpers.from_rfc3339(value) == datetime.datetime(
+        2009, 12, 17, 12, 44, 32, micros, pytz.utc
+    )
+
+
+def test_from_rfc3339_nanos_is_deprecated():
+    value = "2009-12-17T12:44:32.123456Z"
 
-    with pytest.raises(ValueError):
-        datetime_helpers.from_rfc3339_nanos(value)
+    result = datetime_helpers.from_rfc3339(value)
+    result_nanos = datetime_helpers.from_rfc3339_nanos(value)
+
+    assert result == result_nanos
 
 
 @pytest.mark.parametrize(
@@ -130,6 +152,18 @@ def test_from_rfc3339_nanos_with_truncated_nanos(truncated, micros):
     )
 
 
+def test_from_rfc3339_wo_nanos_raise_exception():
+    value = "2009-12-17T12:44:32"
+    with pytest.raises(ValueError):
+        datetime_helpers.from_rfc3339(value)
+
+
+def test_from_rfc3339_w_nanos_raise_exception():
+    value = "2009-12-17T12:44:32.123456"
+    with pytest.raises(ValueError):
+        datetime_helpers.from_rfc3339(value)
+
+
 def test_to_rfc3339():
     value = datetime.datetime(2016, 4, 5, 13, 30, 0)
     expected = "2016-04-05T13:30:00.000000Z"
@@ -157,10 +191,11 @@ def test_to_rfc3339_with_non_utc_ignore_zone():
 
 
 class Test_DateTimeWithNanos(object):
-
     @staticmethod
     def test_ctor_wo_nanos():
-        stamp = datetime_helpers.DatetimeWithNanoseconds(2016, 12, 20, 21, 13, 47, 123456)
+        stamp = datetime_helpers.DatetimeWithNanoseconds(
+            2016, 12, 20, 21, 13, 47, 123456
+        )
         assert stamp.year == 2016
         assert stamp.month == 12
         assert stamp.day == 20
@@ -200,7 +235,9 @@ def test_ctor_w_micros_keyword_and_nanos():
 
     @staticmethod
     def test_rfc3339_wo_nanos():
-        stamp = datetime_helpers.DatetimeWithNanoseconds(2016, 12, 20, 21, 13, 47, 123456)
+        stamp = datetime_helpers.DatetimeWithNanoseconds(
+            2016, 12, 20, 21, 13, 47, 123456
+        )
         assert stamp.rfc3339() == "2016-12-20T21:13:47.123456Z"
 
     @staticmethod
@@ -285,12 +322,16 @@ def test_from_rfc3339_w_full_precision():
     )
     def test_from_rfc3339_test_nanoseconds(fractional, nanos):
         value = "2009-12-17T12:44:32.{}Z".format(fractional)
-        assert datetime_helpers.DatetimeWithNanoseconds.from_rfc3339(value).nanosecond == nanos
+        assert (
+            datetime_helpers.DatetimeWithNanoseconds.from_rfc3339(value).nanosecond
+            == nanos
+        )
 
     @staticmethod
     def test_timestamp_pb_wo_nanos_naive():
         stamp = datetime_helpers.DatetimeWithNanoseconds(
-            2016, 12, 20, 21, 13, 47, 123456)
+            2016, 12, 20, 21, 13, 47, 123456
+        )
         delta = stamp.replace(tzinfo=pytz.UTC) - datetime_helpers._UTC_EPOCH
         seconds = int(delta.total_seconds())
         nanos = 123456000
@@ -304,7 +345,8 @@ def test_timestamp_pb_w_nanos():
         )
         delta = stamp - datetime_helpers._UTC_EPOCH
         timestamp = timestamp_pb2.Timestamp(
-            seconds=int(delta.total_seconds()), nanos=123456789)
+            seconds=int(delta.total_seconds()), nanos=123456789
+        )
         assert stamp.timestamp_pb() == timestamp
 
     @staticmethod
@@ -314,8 +356,7 @@ def test_from_timestamp_pb_wo_nanos():
         seconds = int(delta.total_seconds())
         timestamp = timestamp_pb2.Timestamp(seconds=seconds)
 
-        stamp = datetime_helpers.DatetimeWithNanoseconds.from_timestamp_pb(
-            timestamp)
+        stamp = datetime_helpers.DatetimeWithNanoseconds.from_timestamp_pb(timestamp)
 
         assert _to_seconds(when) == _to_seconds(stamp)
         assert stamp.microsecond == 0
@@ -329,8 +370,7 @@ def test_from_timestamp_pb_w_nanos():
         seconds = int(delta.total_seconds())
         timestamp = timestamp_pb2.Timestamp(seconds=seconds, nanos=123456789)
 
-        stamp = datetime_helpers.DatetimeWithNanoseconds.from_timestamp_pb(
-            timestamp)
+        stamp = datetime_helpers.DatetimeWithNanoseconds.from_timestamp_pb(timestamp)
 
         assert _to_seconds(when) == _to_seconds(stamp)
         assert stamp.microsecond == 123456