refactor

Author: quangngd

pandas/_libs/tslibs/tzconversion.pyx

@@ -237,7 +237,7 @@ timedelta-like}
         Py_ssize_t i, n = vals.shape[0]
         Py_ssize_t delta_idx_offset, delta_idx
         int64_t v, left, right, val, new_local, remaining_mins
-        int64_t first_delta, delta
+        int64_t delta
         int64_t shift_delta = 0
         ndarray[int64_t] result_a, result_b, dst_hours
         int64_t[::1] result
@@ -327,22 +327,6 @@ timedelta-like}
     if infer_dst:
         dst_hours = _get_dst_hours(vals, result_a, result_b, creso=creso)
 
-    # Pre-compute delta_idx_offset that will be used if we go down non-existent
-    #  paths.
-    # Shift the delta_idx by if the UTC offset of
-    # the target tz is greater than 0 and we're moving forward
-    # or vice versa
-    # TODO: delta_idx_offset and info.deltas are needed for zoneinfo timezones,
-    # but are not applicable for all timezones. Setting the former to 0 and
-    # length checking the latter avoids UB, but this could use a larger refactor
-    delta_idx_offset = 0
-    if len(info.deltas):
-        first_delta = info.deltas[0]
-        if (shift_forward or shift_delta > 0) and first_delta > 0:
-            delta_idx_offset = 1
-        elif (shift_backward or shift_delta < 0) and first_delta < 0:
-            delta_idx_offset = 1
-
     for i in range(n):
         val = vals[i]
         left = result_a[i]
@@ -416,9 +400,21 @@ timedelta-like}
 
                 else:
                     delta_idx = bisect_right_i8(info.tdata, new_local, info.ntrans)
-                    if (shift_forward or shift_delta > 0) and \
-                       info.deltas[delta_idx-1] >= 0:
-                        delta_idx_offset = 1
+
+                    # Shift the delta_idx by if the UTC offset of
+                    # the target tz is greater than 0 and we're moving forward
+                    # or vice versa
+                    # TODO: delta_idx_offset and info.deltas are needed for zoneinfo
+                    # timezones, but are not applicable for all timezones. Setting the
+                    # former to 0 and length checking the latter avoids UB, but this
+                    # could use a larger refactor
+                    delta_idx_offset = 0
+                    if len(info.deltas):
+                        delta = info.deltas[delta_idx-1]
+                        if (shift_forward or shift_delta > 0) and delta >= 0:
+                            delta_idx_offset = 1
+                        elif (shift_backward or shift_delta < 0) and delta < 0:
+                            delta_idx_offset = 1
 
                     delta_idx = delta_idx - delta_idx_offset
                     result[i] = new_local - info.deltas[delta_idx]