MAINT: Conversion of some strings to fstrings, part III (#17623)

* Conversion of some strings to fstrings

* Remove spaces

* Update numpy/ma/mrecords.py

Co-authored-by: Bas van Beek <43369155+BvB93@users.noreply.github.com>

* Update numpy/ma/tests/test_old_ma.py

Co-authored-by: Bas van Beek <43369155+BvB93@users.noreply.github.com>

* Update numpy/ma/timer_comparison.py

Co-authored-by: Bas van Beek <43369155+BvB93@users.noreply.github.com>

Co-authored-by: Jakob <jakobjakobson13@posteo.de>
Co-authored-by: Bas van Beek <43369155+BvB93@users.noreply.github.com>

7 files changed, 37 insertions, 38 deletions

diff --git a/numpy/ma/bench.py b/numpy/ma/bench.py
index 83cc6aea7..e29d54365 100644
--- a/numpy/ma/bench.py
+++ b/numpy/ma/bench.py
@@ -58,7 +58,7 @@ def compare_functions_1v(func, nloop=500,
                        xs=xs, nmxs=nmxs, xl=xl, nmxl=nmxl):
     funcname = func.__name__
     print("-"*50)
-    print("%s on small arrays" % funcname)
+    print(f'{funcname} on small arrays')
     module, data = "numpy.ma", "nmxs"
     timer("%(module)s.%(funcname)s(%(data)s)" % locals(), v="%11s" % module, nloop=nloop)
 
@@ -70,8 +70,8 @@ def compare_functions_1v(func, nloop=500,
 def compare_methods(methodname, args, vars='x', nloop=500, test=True,
                     xs=xs, nmxs=nmxs, xl=xl, nmxl=nmxl):
     print("-"*50)
-    print("%s on small arrays" % methodname)
-    data, ver = "nm%ss" % vars, 'numpy.ma'
+    print(f'{methodname} on small arrays')
+    data, ver = f'nm{vars}l', 'numpy.ma'
     timer("%(data)s.%(methodname)s(%(args)s)" % locals(), v=ver, nloop=nloop)
 
     print("%s on large arrays" % methodname)
@@ -86,11 +86,11 @@ def compare_functions_2v(func, nloop=500, test=True,
                        yl=yl, nmyl=nmyl):
     funcname = func.__name__
     print("-"*50)
-    print("%s on small arrays" % funcname)
+    print(f'{funcname} on small arrays')
     module, data = "numpy.ma", "nmxs,nmys"
     timer("%(module)s.%(funcname)s(%(data)s)" % locals(), v="%11s" % module, nloop=nloop)
 
-    print("%s on large arrays" % funcname)
+    print(f'{funcname} on large arrays')
     module, data = "numpy.ma", "nmxl,nmyl"
     timer("%(module)s.%(funcname)s(%(data)s)" % locals(), v="%11s" % module, nloop=nloop)
     return
diff --git a/numpy/ma/mrecords.py b/numpy/ma/mrecords.py
index c017bee95..70087632e 100644
--- a/numpy/ma/mrecords.py
+++ b/numpy/ma/mrecords.py
@@ -60,7 +60,7 @@ def _checknames(descr, names=None):
         elif isinstance(names, str):
             new_names = names.split(',')
         else:
-            raise NameError("illegal input names %s" % repr(names))
+            raise NameError(f'illegal input names {names!r}')
         nnames = len(new_names)
         if nnames < ndescr:
             new_names += default_names[nnames:]
@@ -199,7 +199,7 @@ class MaskedRecords(MaskedArray):
         try:
             res = fielddict[attr][:2]
         except (TypeError, KeyError) as e:
-            raise AttributeError("record array has no attribute %s" % attr) from e
+            raise AttributeError(f'record array has no attribute {attr}') from e
         # So far, so good
         _localdict = ndarray.__getattribute__(self, '__dict__')
         _data = ndarray.view(self, _localdict['_baseclass'])
@@ -274,7 +274,7 @@ class MaskedRecords(MaskedArray):
         try:
             res = fielddict[attr][:2]
         except (TypeError, KeyError):
-            raise AttributeError("record array has no attribute %s" % attr)
+            raise AttributeError(f'record array has no attribute {attr}')
 
         if val is masked:
             _fill_value = _localdict['_fill_value']
@@ -337,13 +337,13 @@ class MaskedRecords(MaskedArray):
 
         """
         if self.size > 1:
-            mstr = ["(%s)" % ",".join([str(i) for i in s])
+            mstr = [f"({','.join([str(i) for i in s])})"
                     for s in zip(*[getattr(self, f) for f in self.dtype.names])]
-            return "[%s]" % ", ".join(mstr)
+            return f"[{', '.join(mstr)}]"
         else:
-            mstr = ["%s" % ",".join([str(i) for i in s])
+            mstr = [f"{','.join([str(i) for i in s])}"
                     for s in zip([getattr(self, f) for f in self.dtype.names])]
-            return "(%s)" % ", ".join(mstr)
+            return f"({', '.join(mstr)})"
 
     def __repr__(self):
         """
@@ -657,7 +657,7 @@ def openfile(fname):
     try:
         f = open(fname)
     except IOError:
-        raise IOError("No such file: '%s'" % fname)
+        raise IOError(f"No such file: '{fname}'")
     if f.readline()[:2] != "\\x":
         f.seek(0, 0)
         return f
diff --git a/numpy/ma/tests/test_core.py b/numpy/ma/tests/test_core.py
index 0ed2971e6..6a2ed8ca7 100644
--- a/numpy/ma/tests/test_core.py
+++ b/numpy/ma/tests/test_core.py
@@ -2748,7 +2748,7 @@ class TestMaskedArrayInPlaceArithmetics:
                 xm += t(1)
                 assert_equal(xm, y + t(1))
 
-                assert_equal(len(w), 0, "Failed on type=%s." % t)
+                assert_equal(len(w), 0, f'Failed on type={t}.')
 
     def test_inplace_addition_array_type(self):
         # Test of inplace additions
@@ -2765,7 +2765,7 @@ class TestMaskedArrayInPlaceArithmetics:
                 assert_equal(xm, y + a)
                 assert_equal(xm.mask, mask_or(m, a.mask))
 
-                assert_equal(len(w), 0, "Failed on type=%s." % t)
+                assert_equal(len(w), 0, f'Failed on type={t}.')
 
     def test_inplace_subtraction_scalar_type(self):
         # Test of inplace subtractions
@@ -2778,7 +2778,7 @@ class TestMaskedArrayInPlaceArithmetics:
                 xm -= t(1)
                 assert_equal(xm, y - t(1))
 
-                assert_equal(len(w), 0, "Failed on type=%s." % t)
+                assert_equal(len(w), 0, f'Failed on type={t}.')
 
     def test_inplace_subtraction_array_type(self):
         # Test of inplace subtractions
@@ -2795,7 +2795,7 @@ class TestMaskedArrayInPlaceArithmetics:
                 assert_equal(xm, y - a)
                 assert_equal(xm.mask, mask_or(m, a.mask))
 
-                assert_equal(len(w), 0, "Failed on type=%s." % t)
+                assert_equal(len(w), 0, f'Failed on type={t}.')
 
     def test_inplace_multiplication_scalar_type(self):
         # Test of inplace multiplication
@@ -2808,7 +2808,7 @@ class TestMaskedArrayInPlaceArithmetics:
                 xm *= t(2)
                 assert_equal(xm, y * t(2))
 
-                assert_equal(len(w), 0, "Failed on type=%s." % t)
+                assert_equal(len(w), 0, f'Failed on type={t}.')
 
     def test_inplace_multiplication_array_type(self):
         # Test of inplace multiplication
@@ -2825,7 +2825,7 @@ class TestMaskedArrayInPlaceArithmetics:
                 assert_equal(xm, y * a)
                 assert_equal(xm.mask, mask_or(m, a.mask))
 
-                assert_equal(len(w), 0, "Failed on type=%s." % t)
+                assert_equal(len(w), 0, f'Failed on type={t}.')
 
     def test_inplace_floor_division_scalar_type(self):
         # Test of inplace division
@@ -2861,7 +2861,7 @@ class TestMaskedArrayInPlaceArithmetics:
                     mask_or(mask_or(m, a.mask), (a == t(0)))
                 )
 
-                assert_equal(len(w), 0, "Failed on type=%s." % t)
+                assert_equal(len(w), 0, f'Failed on type={t}.')
 
     def test_inplace_division_scalar_type(self):
         # Test of inplace division
@@ -2895,9 +2895,9 @@ class TestMaskedArrayInPlaceArithmetics:
                     warnings.warn(str(e), stacklevel=1)
 
                 if issubclass(t, np.integer):
-                    assert_equal(len(sup.log), 2, "Failed on type=%s." % t)
+                    assert_equal(len(sup.log), 2, f'Failed on type={t}.')
                 else:
-                    assert_equal(len(sup.log), 0, "Failed on type=%s." % t)
+                    assert_equal(len(sup.log), 0, f'Failed on type={t}.')
 
     def test_inplace_division_array_type(self):
         # Test of inplace division
@@ -2934,9 +2934,9 @@ class TestMaskedArrayInPlaceArithmetics:
                     warnings.warn(str(e), stacklevel=1)
 
                 if issubclass(t, np.integer):
-                    assert_equal(len(sup.log), 2, "Failed on type=%s." % t)
+                    assert_equal(len(sup.log), 2, f'Failed on type={t}.')
                 else:
-                    assert_equal(len(sup.log), 0, "Failed on type=%s." % t)
+                    assert_equal(len(sup.log), 0, f'Failed on type={t}.')
 
     def test_inplace_pow_type(self):
         # Test keeping data w/ (inplace) power
@@ -2954,7 +2954,7 @@ class TestMaskedArrayInPlaceArithmetics:
                 assert_equal(x.data, xx_r.data)
                 assert_equal(x.mask, xx_r.mask)
 
-                assert_equal(len(w), 0, "Failed on type=%s." % t)
+                assert_equal(len(w), 0, f'Failed on type={t}.')
 
 
 class TestMaskedArrayMethods:
diff --git a/numpy/ma/tests/test_old_ma.py b/numpy/ma/tests/test_old_ma.py
index 96c7e3609..ab003b94e 100644
--- a/numpy/ma/tests/test_old_ma.py
+++ b/numpy/ma/tests/test_old_ma.py
@@ -27,7 +27,7 @@ pi = np.pi
 def eq(v, w, msg=''):
     result = allclose(v, w)
     if not result:
-        print("Not eq:%s\n%s\n----%s" % (msg, str(v), str(w)))
+        print(f'Not eq:{msg}\n{v}\n----{w}')
     return result
 
 
diff --git a/numpy/ma/tests/test_subclassing.py b/numpy/ma/tests/test_subclassing.py
index caa746740..f2623406d 100644
--- a/numpy/ma/tests/test_subclassing.py
+++ b/numpy/ma/tests/test_subclassing.py
@@ -109,11 +109,11 @@ class CSAIterator:
 class ComplicatedSubArray(SubArray):
 
     def __str__(self):
-        return 'myprefix {0} mypostfix'.format(self.view(SubArray))
+        return f'myprefix {self.view(SubArray)} mypostfix'
 
     def __repr__(self):
         # Return a repr that does not start with 'name('
-        return '<{0} {1}>'.format(self.__class__.__name__, self)
+        return f'<{self.__class__.__name__} {self}>'
 
     def _validate_input(self, value):
         if not isinstance(value, ComplicatedSubArray):
@@ -317,8 +317,8 @@ class TestSubclassing:
         assert_startswith(repr(mx), 'masked_array')
         xsub = SubArray(x)
         mxsub = masked_array(xsub, mask=[True, False, True, False, False])
-        assert_startswith(repr(mxsub),
-            'masked_{0}(data=[--, 1, --, 3, 4]'.format(SubArray.__name__))
+        assert_startswith(repr(mxsub), 
+            f'masked_{SubArray.__name__}(data=[--, 1, --, 3, 4]')
 
     def test_subclass_str(self):
         """test str with subclass that has overridden str, setitem"""
diff --git a/numpy/ma/testutils.py b/numpy/ma/testutils.py
index 51ab03948..8d55e1763 100644
--- a/numpy/ma/testutils.py
+++ b/numpy/ma/testutils.py
@@ -86,7 +86,7 @@ def _assert_equal_on_sequences(actual, desired, err_msg=''):
     """
     assert_equal(len(actual), len(desired), err_msg)
     for k in range(len(desired)):
-        assert_equal(actual[k], desired[k], 'item=%r\n%s' % (k, err_msg))
+        assert_equal(actual[k], desired[k], f'item={k!r}\n{err_msg}')
     return
 
 
@@ -117,8 +117,8 @@ def assert_equal(actual, desired, err_msg=''):
         assert_equal(len(actual), len(desired), err_msg)
         for k, i in desired.items():
             if k not in actual:
-                raise AssertionError("%s not in %s" % (k, actual))
-            assert_equal(actual[k], desired[k], 'key=%r\n%s' % (k, err_msg))
+                raise AssertionError(f"{k} not in {actual}")
+            assert_equal(actual[k], desired[k], f'key={k!r}\n{err_msg}')
         return
     # Case #2: lists .....
     if isinstance(desired, (list, tuple)) and isinstance(actual, (list, tuple)):
@@ -156,12 +156,12 @@ def fail_if_equal(actual, desired, err_msg='',):
         for k, i in desired.items():
             if k not in actual:
                 raise AssertionError(repr(k))
-            fail_if_equal(actual[k], desired[k], 'key=%r\n%s' % (k, err_msg))
+            fail_if_equal(actual[k], desired[k], f'key={k!r}\n{err_msg}')
         return
     if isinstance(desired, (list, tuple)) and isinstance(actual, (list, tuple)):
         fail_if_equal(len(actual), len(desired), err_msg)
         for k in range(len(desired)):
-            fail_if_equal(actual[k], desired[k], 'item=%r\n%s' % (k, err_msg))
+            fail_if_equal(actual[k], desired[k], f'item={k!r}\n{err_msg}')
         return
     if isinstance(actual, np.ndarray) or isinstance(desired, np.ndarray):
         return fail_if_array_equal(actual, desired, err_msg)
diff --git a/numpy/ma/timer_comparison.py b/numpy/ma/timer_comparison.py
index f5855efcf..aff72f79b 100644
--- a/numpy/ma/timer_comparison.py
+++ b/numpy/ma/timer_comparison.py
@@ -77,8 +77,7 @@ class ModuleTester:
             if not cond:
                 msg = build_err_msg([x, y],
                                     err_msg
-                                    + '\n(shapes %s, %s mismatch)' % (x.shape,
-                                                                      y.shape),
+                                    + f'\n(shapes {x.shape}, {y.shape} mismatch)',
                                     header=header,
                                     names=('x', 'y'))
                 assert cond, msg
@@ -434,4 +433,4 @@ if __name__ == '__main__':
         cur = np.sort(cur)
         print("#%i" % i + 50*'.')
         print(eval("ModuleTester.test_%i.__doc__" % i))
-        print("core_current : %.3f - %.3f" % (cur[0], cur[1]))
+        print(f'core_current : {cur[0]:.3f} - {cur[1]:.3f}')