Change exception string, move str check out

Author: pdnm

pandas/_libs/tslibs/timedeltas.pyx

@@ -234,15 +234,17 @@ def array_to_timedelta64(object[:] values, unit=None, errors='raise'):
     n = values.shape[0]
     result = np.empty(n, dtype='m8[ns]')
     iresult = result.view('i8')
-    has_string = False
+    
+    if unit is not None:
+        for i in range(n):
+            if isinstance(values[i], str):
+                raise ValueError("unit must not be specified if the input contains a str")
 
     # Usually, we have all strings. If so, we hit the fast path.
     # If this path fails, we try conversion a different way, and
     # this is where all of the error handling will take place.
     try:
         for i in range(n):
-            if isinstance(values[i], str):
-                has_string = True
             if values[i] is NaT:
                 # we allow this check in the fast-path because NaT is a C-object
                 #  so this is an inexpensive check
@@ -260,9 +262,6 @@ def array_to_timedelta64(object[:] values, unit=None, errors='raise'):
                 else:
                     raise
 
-    if has_string and unit is not None:
-        raise ValueError("unit must be un-specified if the input contains a str")
-
     return iresult.base  # .base to access underlying np.ndarray
 
 
@@ -1162,7 +1161,7 @@ class Timedelta(_Timedelta):
             value = value.value
         elif isinstance(value, str):
             if unit is not None:
-                raise ValueError("unit must be un-specified if the value is a str")
+                raise ValueError("unit must not be specified if the value is a str")
             if len(value) > 0 and value[0] == 'P':
                 value = parse_iso_format_string(value)
             else:

pandas/core/arrays/timedeltas.py

@@ -1014,7 +1014,7 @@ def objects_to_td64ns(data, unit=None, errors="raise"):
     data : ndarray or Index
     unit : str, default "ns"
         The timedelta unit to treat integers as multiples of.
-        Must be un-specified if the data contains a str.
+        Must not be specified if the data contains a str.
     errors : {"raise", "coerce", "ignore"}, default "raise"
         How to handle elements that cannot be converted to timedelta64[ns].
         See ``pandas.to_timedelta`` for details.

pandas/core/tools/timedeltas.py

@@ -27,7 +27,7 @@ def to_timedelta(arg, unit=None, errors="raise"):
     arg : str, timedelta, list-like or Series
         The data to be converted to timedelta.
     unit : str, default 'ns'
-        Must be un-specified if the arg is/contains a str.
+        Must not be specified if the arg is/contains a str.
         Denotes the unit of the arg. Possible values:
         ('W', 'D', 'days', 'day', 'hours', hour', 'hr', 'h',
         'm', 'minute', 'min', 'minutes', 'T', 'S', 'seconds',
@@ -107,7 +107,7 @@ def to_timedelta(arg, unit=None, errors="raise"):
         )
 
     if isinstance(arg, str) and unit is not None:
-        raise ValueError("unit must be un-specified if the input is/contains a str")
+        raise ValueError("unit must not be specified if the input is/contains a str")
 
     # ...so it must be a scalar value. Return scalar.
     return _coerce_scalar_to_timedelta_type(arg, unit=unit, errors=errors)

pandas/tests/scalar/timedelta/test_constructors.py

@@ -294,9 +294,9 @@ def test_timedelta_constructor_identity():
 @pytest.mark.parametrize(
     "constructor, value, unit, expectation",
     [
-        (Timedelta, "10s", "ms", (ValueError, "unit must be un-specified")),
-        (to_timedelta, "10s", "ms", (ValueError, "unit must be un-specified")),
-        (to_timedelta, ["1", 2, 3], "s", (ValueError, "unit must be un-specified")),
+        (Timedelta, "10s", "ms", (ValueError, "unit must not be specified")),
+        (to_timedelta, "10s", "ms", (ValueError, "unit must not be specified")),
+        (to_timedelta, ["1", 2, 3], "s", (ValueError, "unit must not be specified")),
     ],
 )
 def test_string_with_unit(constructor, value, unit, expectation):