Fix missing seconds when formatting timezone offset (#961)

CHANGELOG.rst

@@ -6,6 +6,7 @@
 - Fix file possibly rotating too early or too late when re-starting an application around midnight (`#894 <https://github.com/Delgan/loguru/issues/894>`_).
 - Fix inverted ``"<hide>"`` and ``"<strike>"`` color tags (`#943 <https://github.com/Delgan/loguru/pull/943>`_, thanks `@tunaflsh <https://github.com/tunaflsh>`_).
 - Fix possible errors raised by logging non-picklable ``Exception`` instances while using ``enqueue=True`` (`#342 <https://github.com/Delgan/loguru/issues/342>`_, thanks `@ncoudene <https://github.com/ncoudene>`_).
+- Fix missing seconds and microseconds when formatting timezone offset that requires such accuracy (`#961 <https://github.com/Delgan/loguru/issues/961>`_).
 - Raise ``ValueError`` if an attempt to use nanosecond precision for time formatting is detected (`#855 <https://github.com/Delgan/loguru/issues/855>`_).
 
 

loguru/_datetime.py

@@ -36,7 +36,7 @@ def __format__(self, spec):
         tzinfo = dt.tzinfo or timezone(timedelta(seconds=0))
         offset = tzinfo.utcoffset(dt).total_seconds()
         sign = ("-", "+")[offset >= 0]
-        h, m = divmod(abs(offset // 60), 60)
+        (h, m), s = divmod(abs(offset // 60), 60), abs(offset) % 60
 
         rep = {
             "YYYY": "%04d" % year,
@@ -69,8 +69,8 @@ def __format__(self, spec):
             "SSSSS": "%05d" % (microsecond // 10),
             "SSSSSS": "%06d" % microsecond,
             "A": ("AM", "PM")[hour // 12],
-            "Z": "%s%02d:%02d" % (sign, h, m),
-            "ZZ": "%s%02d%02d" % (sign, h, m),
+            "Z": "%s%02d:%02d%s" % (sign, h, m, (":%09.06f" % s)[: 11 if s % 1 else 3] * (s > 0)),
+            "ZZ": "%s%02d%02d%s" % (sign, h, m, ("%09.06f" % s)[: 10 if s % 1 else 2] * (s > 0)),
             "zz": tzinfo.tzname(dt) or "",
             "X": "%d" % timestamp,
             "x": "%d" % (int(timestamp) * 1000000 + microsecond),

tests/test_datetime.py

@@ -115,6 +115,26 @@ def test_formatting(writer, freeze_time, time_format, date, timezone, expected):
         assert result == expected + "\n"
 
 
+@pytest.mark.parametrize(
+    "time_format, offset, expected",
+    [
+        ("%Y-%m-%d %H-%M-%S %f %Z %z", 7230.099, "2018-06-09 01-02-03 000000 ABC +020030.099000"),
+        ("YYYY-MM-DD HH-mm-ss zz Z ZZ", 6543, "2018-06-09 01-02-03 ABC +01:49:03 +014903"),
+        ("HH-mm-ss zz Z ZZ", -12345.06702, "01-02-03 ABC -03:26:45.067020 -032645.067020"),
+    ],
+)
+@pytest.mark.skipif(sys.version_info < (3, 7), reason="Offset must be a whole number of minutes")
+def test_formatting_timezone_offset_down_to_the_second(
+    writer, freeze_time, time_format, offset, expected
+):
+    date = datetime.datetime(2018, 6, 9, 1, 2, 3)
+    with freeze_time(date, ("ABC", offset)):
+        logger.add(writer, format="{time:%s}" % time_format)
+        logger.debug("Test")
+        result = writer.read()
+        assert result == expected + "\n"
+
+
 def test_locale_formatting(writer, freeze_time):
     dt = datetime.datetime(2011, 1, 1, 22, 22, 22, 0)
     with freeze_time(dt):