Backport PR astropy#16426: BUG: fix compatibility with numpy 2 in dif…

…f reports (io.fits, utils)

astropy/io/fits/diff.py

@@ -1112,7 +1112,8 @@ def _report(self):
             return
 
         for index, values in self.diff_pixels:
-            index = [x + 1 for x in reversed(index)]
+            # Convert to int to avoid np.int64 in list repr.
+            index = [int(x + 1) for x in reversed(index)]
             self._writeln(f" Data differs at {index}:")
             report_diff_values(
                 values[0],

astropy/io/fits/tests/test_diff.py

@@ -658,6 +658,7 @@ def test_partially_identical_files1(self):
         assert "a: 2\n b: 3" in report
         assert "No differences found between common HDUs" in report
 
+    @pytest.mark.usefixtures("without_legacy_printoptions")
     def test_partially_identical_files2(self):
         """
         Test files that have some identical HDUs but one different HDU.

astropy/io/fits/tests/test_fitsdiff.py

@@ -64,6 +64,7 @@ def test_onediff(self):
         numdiff = fitsdiff.main([tmp_a, tmp_b])
         assert numdiff == 1
 
+    @pytest.mark.usefixtures("without_legacy_printoptions")
     def test_manydiff(self, capsys):
         a = np.arange(100).reshape(10, 10)
         hdu_a = PrimaryHDU(data=a)
@@ -94,6 +95,7 @@ def test_manydiff(self, capsys):
             "     100 different pixels found (100.00% different).",
         ]
 
+    @pytest.mark.usefixtures("without_legacy_printoptions")
     def test_outputfile(self):
         a = np.arange(100).reshape(10, 10)
         hdu_a = PrimaryHDU(data=a)
@@ -146,6 +148,7 @@ def test_rtol(self):
         numdiff = fitsdiff.main(["-r", "1e-1", tmp_a, tmp_b])
         assert numdiff == 0
 
+    @pytest.mark.usefixtures("without_legacy_printoptions")
     def test_rtol_diff(self, capsys):
         a = np.arange(100, dtype=float).reshape(10, 10)
         hdu_a = PrimaryHDU(data=a)

astropy/utils/diff.py

@@ -1,6 +1,5 @@
 import difflib
 import functools
-import numbers
 import sys
 from textwrap import indent
 
@@ -126,12 +125,8 @@ def report_diff_values(a, b, fileobj=sys.stdout, indent_width=0, rtol=0.0, atol=
         lnpad = " "
         sign_a = "a>"
         sign_b = "b>"
-        if isinstance(a, numbers.Number):
-            a = repr(a)
-            b = repr(b)
-        else:
-            a = str(a)
-            b = str(b)
+        a = str(a)
+        b = str(b)
     else:
         padding = max(len(typea.__name__), len(typeb.__name__)) + 3
         lnpad = (padding + 1) * " "
@@ -140,22 +135,8 @@ def report_diff_values(a, b, fileobj=sys.stdout, indent_width=0, rtol=0.0, atol=
 
         is_a_str = isinstance(a, str)
         is_b_str = isinstance(b, str)
-        a = (
-            repr(a)
-            if (
-                (is_a_str and not is_b_str)
-                or (not is_a_str and isinstance(a, numbers.Number))
-            )
-            else str(a)
-        )
-        b = (
-            repr(b)
-            if (
-                (is_b_str and not is_a_str)
-                or (not is_b_str and isinstance(b, numbers.Number))
-            )
-            else str(b)
-        )
+        a = repr(a) if is_a_str and not is_b_str else str(a)
+        b = repr(b) if is_b_str and not is_a_str else str(b)
 
     identical = True
 

docs/changes/io.fits/16426.bugfix.rst

@@ -0,0 +1 @@
+Fix display of diff reports with numpy 2.