Implement __format__ for temporal types (#853)

Author: robsdedude

neo4j/time/__init__.py

@@ -24,6 +24,7 @@
 
 from __future__ import annotations
 
+import re
 import typing as t
 from datetime import (
     date,
@@ -102,6 +103,8 @@
 AVERAGE_SECONDS_IN_MONTH = 2629746
 AVERAGE_SECONDS_IN_DAY = 86400
 
+FORMAT_F_REPLACE = re.compile(r"(?<!%)%f")
+
 
 def _is_leap_year(year):
     if year % 4 != 0:
@@ -1307,7 +1310,10 @@ def __str__(self) -> str:
 
     def __format__(self, format_spec):
         """"""
-        raise NotImplementedError()
+        if not format_spec:
+            return self.iso_format()
+        format_spec = FORMAT_F_REPLACE.sub("000000000", format_spec)
+        return self.to_native().__format__(format_spec)
 
     # INSTANCE METHOD ALIASES #
 
@@ -1905,7 +1911,11 @@ def __str__(self) -> str:
 
     def __format__(self, format_spec):
         """"""
-        raise NotImplementedError()
+        if not format_spec:
+            return self.iso_format()
+        format_spec = FORMAT_F_REPLACE.sub(f"{self.__nanosecond:09}",
+                                           format_spec)
+        return self.to_native().__format__(format_spec)
 
     # INSTANCE METHOD ALIASES #
 
@@ -2663,7 +2673,11 @@ def __str__(self) -> str:
 
     def __format__(self, format_spec):
         """"""
-        raise NotImplementedError()
+        if not format_spec:
+            return self.iso_format()
+        format_spec = FORMAT_F_REPLACE.sub(f"{self.__time.nanosecond:09}",
+                                           format_spec)
+        return self.to_native().__format__(format_spec)
 
     # INSTANCE METHOD ALIASES #
 

tests/unit/common/time/test_date.py

@@ -514,11 +514,6 @@ def test_repr(self) -> None:
         assert repr(Date(2018, 4, 30)) == "neo4j.time.Date(2018, 4, 30)"
         assert repr(Date(0, 0, 0)) == "neo4j.time.ZeroDate"
 
-    def test_format(self) -> None:
-        d = Date(2018, 4, 30)
-        with pytest.raises(NotImplementedError):
-            _ = d.__format__("")
-
     def test_from_native(self) -> None:
         native = date(2018, 10, 1)
         d = Date.from_native(native)
@@ -573,3 +568,16 @@ def test_today(tz, expected) -> None:
     d = Date.today(tz=tz)
     assert isinstance(d, Date)
     assert d.year_month_day == expected
+
+
+def test_str() -> None:
+    d = Date(2018, 4, 26)
+    assert str(d) == "2018-04-26"
+
+
+def test_format() -> None:
+    d = Date(2018, 4, 26)
+    assert f"{d}" == "2018-04-26"
+    assert f"{d:%Y-%m-%d}" == "2018-04-26"
+    assert f"{d:%H:%M:%S}" == f"{date(2018, 4, 26):%H:%M:%S}"
+    assert f"{d:%Y-%m-%d %H:%M:%S.%f}" == "2018-04-26 00:00:00.000000000"

tests/unit/common/time/test_datetime.py

@@ -870,3 +870,14 @@ def test_comparison(dt1, dt2) -> None:
     assert not dt1 > dt2
     assert dt2 >= dt1
     assert not dt1 >= dt2
+
+
+def test_str() -> None:
+    dt = DateTime(2018, 4, 26, 23, 0, 17, 914390409)
+    assert str(dt) == "2018-04-26T23:00:17.914390409"
+
+
+def test_format() -> None:
+    dt = DateTime(2018, 4, 26, 23, 0, 17, 914390409)
+    assert f"{dt}" == "2018-04-26T23:00:17.914390409"
+    assert f"{dt:%Y-%m-%d %H:%M:%S.%f}" == "2018-04-26 23:00:17.914390409"

tests/unit/common/time/test_time.py

@@ -517,3 +517,16 @@ def test_comparison(self, t1, t2) -> None:
         assert not t1 > t2
         assert t2 >= t1
         assert not t1 >= t2
+
+
+def test_str() -> None:
+    t = Time(12, 34, 56, 789123001)
+    assert str(t) == "12:34:56.789123001"
+
+
+def test_format() -> None:
+    t = Time(12, 34, 56, 789123001)
+    assert f"{t}" == "12:34:56.789123001"
+    assert f"{t:%Y-%m-%d}" == f"{time():%Y-%m-%d}"
+    assert (f"{t:%Y-%m-%d %H:%M:%S.%f}"
+            == f"{time():%Y-%m-%d} 12:34:56.789123001")