CLN: assorted tslibs cleanups, annotations

pandas/_libs/tslibs/conversion.pyx

@@ -77,7 +77,7 @@ cdef inline int64_t cast_from_unit(object ts, str unit) except? -1:
     return <int64_t>(base * m) + <int64_t>(frac * m)
 
 
-cpdef inline object precision_from_unit(str unit):
+cpdef inline (int64_t, int) precision_from_unit(str unit):
     """
     Return a casting of the unit represented to nanoseconds + the precision
     to round the fractional part.

pandas/_libs/tslibs/fields.pyx

@@ -91,7 +91,7 @@ def build_field_sarray(const int64_t[:] dtindex):
 
 @cython.wraparound(False)
 @cython.boundscheck(False)
-def get_date_name_field(const int64_t[:] dtindex, object field, object locale=None):
+def get_date_name_field(const int64_t[:] dtindex, str field, object locale=None):
     """
     Given a int64-based datetime index, return array of strings of date
     name based on requested field (e.g. day_name)
@@ -141,7 +141,7 @@ def get_date_name_field(const int64_t[:] dtindex, object field, object locale=No
 
 @cython.wraparound(False)
 @cython.boundscheck(False)
-def get_start_end_field(const int64_t[:] dtindex, object field,
+def get_start_end_field(const int64_t[:] dtindex, str field,
                         object freqstr=None, int month_kw=12):
     """
     Given an int64-based datetime index return array of indicators
@@ -386,7 +386,7 @@ def get_start_end_field(const int64_t[:] dtindex, object field,
 
 @cython.wraparound(False)
 @cython.boundscheck(False)
-def get_date_field(const int64_t[:] dtindex, object field):
+def get_date_field(const int64_t[:] dtindex, str field):
     """
     Given a int64-based datetime index, extract the year, month, etc.,
     field and return an array of these values.
@@ -548,7 +548,7 @@ def get_date_field(const int64_t[:] dtindex, object field):
 
 @cython.wraparound(False)
 @cython.boundscheck(False)
-def get_timedelta_field(const int64_t[:] tdindex, object field):
+def get_timedelta_field(const int64_t[:] tdindex, str field):
     """
     Given a int64-based timedelta index, extract the days, hrs, sec.,
     field and return an array of these values.

pandas/_libs/tslibs/nattype.pyx

@@ -50,23 +50,23 @@ _nat_scalar_rules[Py_GE] = False
 # ----------------------------------------------------------------------
 
 
-def _make_nan_func(func_name, doc):
+def _make_nan_func(func_name: str, doc: str):
     def f(*args, **kwargs):
         return np.nan
     f.__name__ = func_name
     f.__doc__ = doc
     return f
 
 
-def _make_nat_func(func_name, doc):
+def _make_nat_func(func_name: str, doc: str):
     def f(*args, **kwargs):
         return c_NaT
     f.__name__ = func_name
     f.__doc__ = doc
     return f
 
 
-def _make_error_func(func_name, cls):
+def _make_error_func(func_name: str, cls):
     def f(*args, **kwargs):
         raise ValueError(f"NaTType does not support {func_name}")
 
@@ -282,31 +282,31 @@ cdef class _NaT(datetime):
         return NPY_NAT
 
     @property
-    def is_leap_year(self):
+    def is_leap_year(self) -> bool:
         return False
 
     @property
-    def is_month_start(self):
+    def is_month_start(self) -> bool:
         return False
 
     @property
-    def is_quarter_start(self):
+    def is_quarter_start(self) -> bool:
         return False
 
     @property
-    def is_year_start(self):
+    def is_year_start(self) -> bool:
         return False
 
     @property
-    def is_month_end(self):
+    def is_month_end(self) -> bool:
         return False
 
     @property
-    def is_quarter_end(self):
+    def is_quarter_end(self) -> bool:
         return False
 
     @property
-    def is_year_end(self):
+    def is_year_end(self) -> bool:
         return False
 
 

pandas/_libs/tslibs/period.pyx

@@ -14,6 +14,7 @@ import cython
 
 from cpython.datetime cimport (
     datetime,
+    tzinfo,
     PyDate_Check,
     PyDateTime_Check,
     PyDateTime_IMPORT,
@@ -1417,7 +1418,7 @@ def extract_freq(ndarray[object] values):
 
 @cython.wraparound(False)
 @cython.boundscheck(False)
-def dt64arr_to_periodarr(const int64_t[:] stamps, int freq, object tz):
+def dt64arr_to_periodarr(const int64_t[:] stamps, int freq, tzinfo tz):
     cdef:
         Py_ssize_t n = len(stamps)
         int64_t[:] result = np.empty(n, dtype=np.int64)

pandas/_libs/tslibs/tzconversion.pyx

@@ -5,7 +5,7 @@ import cython
 from cython import Py_ssize_t
 
 from cpython.datetime cimport (
-    PyDateTime_IMPORT, PyDelta_Check, datetime, tzinfo)
+    PyDateTime_IMPORT, PyDelta_Check, datetime, timedelta, tzinfo)
 PyDateTime_IMPORT
 
 import pytz
@@ -421,23 +421,22 @@ cdef int64_t[:] _tz_convert_one_way(int64_t[:] vals, tzinfo tz, bint to_utc):
     converted : ndarray[int64_t]
     """
     cdef:
-        int64_t[:] converted, result
+        int64_t[:] converted
         Py_ssize_t i, n = len(vals)
         int64_t val
 
-    if not is_utc(tz):
+    if is_utc(tz):
+        converted = vals
+    elif is_tzlocal(tz):
         converted = np.empty(n, dtype=np.int64)
-        if is_tzlocal(tz):
-            for i in range(n):
-                val = vals[i]
-                if val == NPY_NAT:
-                    converted[i] = NPY_NAT
-                else:
-                    converted[i] = _tz_convert_tzlocal_utc(val, tz, to_utc)
-        else:
-            converted = _tz_convert_dst(vals, tz, to_utc)
+        for i in range(n):
+            val = vals[i]
+            if val == NPY_NAT:
+                converted[i] = NPY_NAT
+            else:
+                converted[i] = _tz_convert_tzlocal_utc(val, tz, to_utc)
     else:
-        converted = vals
+        converted = _tz_convert_dst(vals, tz, to_utc)
 
     return converted
 
@@ -471,11 +470,12 @@ cdef inline int64_t _tzlocal_get_offset_components(int64_t val, tzinfo tz,
         npy_datetimestruct dts
         datetime dt
         int64_t delta
+        timedelta td
 
     dt64_to_dtstruct(val, &dts)
     dt = datetime(dts.year, dts.month, dts.day, dts.hour,
                   dts.min, dts.sec, dts.us)
-    # get_utcoffset (tz.utcoffset under the hood) only makes sense if datetime
+    # tz.utcoffset only makes sense if datetime
     # is _wall time_, so if val is a UTC timestamp convert to wall time
     if not to_utc:
         dt = dt.replace(tzinfo=tzutc())
@@ -484,7 +484,8 @@ cdef inline int64_t _tzlocal_get_offset_components(int64_t val, tzinfo tz,
     if fold is not NULL:
         fold[0] = dt.fold
 
-    return int(get_utcoffset(tz, dt).total_seconds()) * 1000000000
+    td = tz.utcoffset(dt)
+    return int(td.total_seconds() * 1_000_000_000)
 
 
 cdef int64_t _tz_convert_tzlocal_utc(int64_t val, tzinfo tz, bint to_utc=True,