Merge pull request numpy#26353 from ngoldbaum/fix-text-padding-nulls

BUG: ensure text padding ufuncs handle stringdtype nan-like nulls

Author: ngoldbaum

numpy/_core/src/umath/stringdtype_ufuncs.cpp

@@ -1625,12 +1625,19 @@ center_ljust_rjust_strided_loop(PyArrayMethod_Context *context,
             Buffer<ENCODING::UTF8> inbuf((char *)s1.buf, s1.size);
             Buffer<ENCODING::UTF8> fill((char *)s2.buf, s2.size);
 
+            size_t num_codepoints = inbuf.num_codepoints();
+            npy_intp width = (npy_intp)*(npy_int64*)in2;
+
+            if (num_codepoints > (size_t)width) {
+                width = num_codepoints;
+            }
+
             char *buf = NULL;
             npy_intp newsize;
             int overflowed = npy_mul_sizes_with_overflow(
                     &(newsize),
                     (npy_intp)num_bytes_for_utf8_character((unsigned char *)s2.buf),
-                    (npy_intp)*(npy_int64*)in2 - inbuf.num_codepoints());
+                    width - num_codepoints);
             newsize += s1.size;
 
             if (overflowed) {
@@ -1752,6 +1759,9 @@ zfill_strided_loop(PyArrayMethod_Context *context,
             Buffer<ENCODING::UTF8> inbuf((char *)is.buf, is.size);
             size_t in_codepoints = inbuf.num_codepoints();
             size_t width = (size_t)*(npy_int64 *)in2;
+            if (in_codepoints > width) {
+                width = in_codepoints;
+            }
             // number of leading one-byte characters plus the size of the
             // original string
             size_t outsize = (width - in_codepoints) + is.size;

numpy/_core/strings.py

@@ -626,7 +626,6 @@ def center(a, width, fillchar=' '):
 
     """
     a = np.asanyarray(a)
-    width = np.maximum(str_len(a), width)
     fillchar = np.asanyarray(fillchar, dtype=a.dtype)
 
     if np.any(str_len(fillchar) != 1):
@@ -636,6 +635,7 @@ def center(a, width, fillchar=' '):
     if a.dtype.char == "T":
         return _center(a, width, fillchar)
 
+    width = np.maximum(str_len(a), width)
     out_dtype = f"{a.dtype.char}{width.max()}"
     shape = np.broadcast_shapes(a.shape, width.shape, fillchar.shape)
     out = np.empty_like(a, shape=shape, dtype=out_dtype)
@@ -682,7 +682,6 @@ def ljust(a, width, fillchar=' '):
 
     """
     a = np.asanyarray(a)
-    width = np.maximum(str_len(a), width)
     fillchar = np.asanyarray(fillchar, dtype=a.dtype)
 
     if np.any(str_len(fillchar) != 1):
@@ -692,6 +691,7 @@ def ljust(a, width, fillchar=' '):
     if a.dtype.char == "T":
         return _ljust(a, width, fillchar)
 
+    width = np.maximum(str_len(a), width)
     shape = np.broadcast_shapes(a.shape, width.shape, fillchar.shape)
     out_dtype = f"{a.dtype.char}{width.max()}"
     out = np.empty_like(a, shape=shape, dtype=out_dtype)
@@ -738,7 +738,6 @@ def rjust(a, width, fillchar=' '):
 
     """
     a = np.asanyarray(a)
-    width = np.maximum(str_len(a), width)
     fillchar = np.asanyarray(fillchar, dtype=a.dtype)
 
     if np.any(str_len(fillchar) != 1):
@@ -748,6 +747,7 @@ def rjust(a, width, fillchar=' '):
     if a.dtype.char == "T":
         return _rjust(a, width, fillchar)
 
+    width = np.maximum(str_len(a), width)
     shape = np.broadcast_shapes(a.shape, width.shape, fillchar.shape)
     out_dtype = f"{a.dtype.char}{width.max()}"
     out = np.empty_like(a, shape=shape, dtype=out_dtype)
@@ -784,11 +784,11 @@ def zfill(a, width):
 
     """
     a = np.asanyarray(a)
-    width = np.maximum(str_len(a), width)
 
     if a.dtype.char == "T":
         return _zfill(a, width)
 
+    width = np.maximum(str_len(a), width)
     shape = np.broadcast_shapes(a.shape, width.shape)
     out_dtype = f"{a.dtype.char}{width.max()}"
     out = np.empty_like(a, shape=shape, dtype=out_dtype)

numpy/_core/tests/test_stringdtype.py

@@ -1210,11 +1210,15 @@ def test_unary(string_array, unicode_array, function_name):
 
 PASSES_THROUGH_NAN_NULLS = [
     "add",
+    "center",
+    "ljust",
     "multiply",
     "replace",
+    "rjust",
     "strip",
     "lstrip",
     "rstrip",
+    "zfill",
 ]
 
 NULLS_ARE_FALSEY = [