Defer importing datetime to improve startup speed

Author: hugovk

src/humanize/time.py

@@ -5,7 +5,6 @@
 
 from __future__ import annotations
 
-import datetime as dt
 from enum import Enum
 from functools import total_ordering
 
@@ -15,6 +14,7 @@
 
 TYPE_CHECKING = False
 if TYPE_CHECKING:
+    import datetime as dt
     from collections.abc import Iterable
     from typing import Any
 
@@ -45,6 +45,8 @@ def __lt__(self, other: Any) -> Any:
 
 
 def _now() -> dt.datetime:
+    import datetime as dt
+
     return dt.datetime.now()
 
 
@@ -68,6 +70,8 @@ def _date_and_delta(value: Any, *, now: dt.datetime | None = None) -> tuple[Any,
 
     If that's not possible, return `(None, value)`.
     """
+    import datetime as dt
+
     if not now:
         now = _now()
     if isinstance(value, dt.datetime):
@@ -122,6 +126,8 @@ def naturaldelta(
 
         assert naturaldelta(later - now) == "30 minutes"
     """
+    import datetime as dt
+
     tmp = Unit[minimum_unit.upper()]
     if tmp not in (Unit.SECONDS, Unit.MILLISECONDS, Unit.MICROSECONDS):
         msg = f"Minimum unit '{minimum_unit}' not supported"
@@ -245,6 +251,8 @@ def naturaltime(
     Returns:
         str: A natural representation of the input in a resolution that makes sense.
     """
+    import datetime as dt
+
     value = _convert_aware_datetime(value)
     when = _convert_aware_datetime(when)
 
@@ -270,6 +278,8 @@ def _convert_aware_datetime(
     value: dt.datetime | dt.timedelta | float | None,
 ) -> Any:
     """Convert aware datetime to naive datetime and pass through any other type."""
+    import datetime as dt
+
     if isinstance(value, dt.datetime) and value.tzinfo is not None:
         value = dt.datetime.fromtimestamp(value.timestamp())
     return value
@@ -283,6 +293,8 @@ def naturalday(value: dt.date | dt.datetime, format: str = "%b %d") -> str:
     formatted according to `format`.
 
     """
+    import datetime as dt
+
     try:
         value = dt.date(value.year, value.month, value.day)
     except AttributeError:
@@ -307,6 +319,8 @@ def naturalday(value: dt.date | dt.datetime, format: str = "%b %d") -> str:
 
 def naturaldate(value: dt.date | dt.datetime) -> str:
     """Like `naturalday`, but append a year for dates more than ~five months away."""
+    import datetime as dt
+
     try:
         value = dt.date(value.year, value.month, value.day)
     except AttributeError: