gh-38740: fixing some suggestions by ruff
    
some by hand, some scripted

in particular, removal of useless parentheses

### 📝 Checklist

- [x] The title is concise and informative.
- [x] The description explains in detail what this PR is about.
- [ ] I have linked a relevant issue or discussion.
- [ ] I have created tests covering the changes.
- [ ] I have updated the documentation and checked the documentation
preview.
    
URL: #38740
Reported by: Frédéric Chapoton
Reviewer(s): Frédéric Chapoton, Kwankyu Lee

Author: Release Manager

src/sage/categories/examples/commutative_additive_semigroups.py

@@ -166,11 +166,10 @@ def __init__(self, parent, iterable):
                 {'a': 2, 'b': 0, 'c': 1, 'd': 5}
             """
             d = {a: 0 for a in parent.alphabet}
-            for a, c in iterable:
-                d[a] = c
+            d.update(iterable)
             ElementWrapper.__init__(self, parent, d)
 
-        def _repr_(self):
+        def _repr_(self) -> str:
             """
             EXAMPLES::
 
@@ -182,8 +181,9 @@ def _repr_(self):
                 0
             """
             d = self.value
-            result = ' + '.join( ("%s*%s" % (d[a],a) if d[a] != 1 else a) for a in sorted(d.keys()) if d[a] != 0)
-            return '0' if result == '' else result
+            result = ' + '.join(("%s*%s" % (d[a], a) if d[a] != 1 else a)
+                                for a in sorted(d.keys()) if d[a] != 0)
+            return '0' if not result else result
 
         def __hash__(self):
             """

src/sage/categories/pushout.py

@@ -3055,13 +3055,11 @@ def merge(self, other):
             codomain = self.codomain().join([self.codomain(), other.codomain()])
         # Get the optional arguments:
         as_field = self.as_field or other.as_field
-        kwds = {}
-        for k,v in self.kwds.items():
-            kwds[k] = v
-        for k,v in other.kwds.items():
+        kwds = dict(self.kwds)
+        for k, v in other.kwds.items():
             if k == 'category':
                 if kwds[k] is not None:
-                    kwds[k] = v.join([v,kwds[k]])
+                    kwds[k] = v.join([v, kwds[k]])
                 else:
                     kwds[k] = v
                 continue

src/sage/coding/code_bounds.py

@@ -737,7 +737,7 @@ def elias_bound_asymp(delta, q):
         0.39912396330...
     """
     r = 1 - 1 / q
-    return RDF((1-entropy(r-sqrt(r*(r-delta)), q)))
+    return RDF(1-entropy(r-sqrt(r*(r-delta)), q))
 
 
 def mrrw1_bound_asymp(delta, q):

src/sage/coding/source_coding/huffman.py

@@ -394,7 +394,7 @@ def encode(self, string):
             'Sage is my most favorite general purpose computer algebra system'
         """
         if self._character_to_code:
-            return "".join((self._character_to_code[x] for x in string))
+            return "".join(self._character_to_code[x] for x in string)
 
     def decode(self, string):
         r"""

src/sage/combinat/interval_posets.py

@@ -3533,8 +3533,7 @@ def profil(gr, vertex):
 
         liste = clockwise_labelling(graph0, -1)[1:]
         relabelling = {l: i for i, l in enumerate(liste)}
-        for l in [-1, -2, -3]:
-            relabelling[l] = l
+        relabelling.update((i, i) for i in [-1, -2, -3])
         new_graph = graph.relabel(relabelling, inplace=False)
 
         dyckword_top = []

src/sage/combinat/root_system/type_reducible.py

@@ -525,7 +525,7 @@ def inject_weights(self, i, v):
             [(1, 1, 0, 0, 0), (0, 0, 0, 1/2, 1/2)]
         """
         shift = self.root_system.cartan_type()._shifts[i]
-        return self._from_dict( dict([(shift+k, c) for (k,c) in v ]))
+        return self._from_dict({shift + k: c for k, c in v})
 
     @cached_method
     def simple_root(self, i):

src/sage/combinat/sf/sfa.py

@@ -1982,7 +1982,7 @@ def _change_by_plethysm(self, x, expr, deg_one):
         # Convert to the power sum
         p = self.realization_of().power()
         p_x = p(x)
-        expr_k = lambda k: expr.subs(**dict([(str(x),x**k) for x in deg_one]))
+        expr_k = lambda k: expr.subs(**{str(x): x**k for x in deg_one})
         f = lambda m,c: (m, c*prod([expr_k(k) for k in m]))
         return self(p_x.map_item(f))
 

src/sage/crypto/mq/rijndael_gf.py

@@ -613,8 +613,8 @@ def __call__(self, text, key, algorithm='encrypt', format='hex'):
         elif algorithm == 'decrypt':
             return self.decrypt(text, key, format)
         else:
-            raise ValueError(("keyword 'algorithm' must be either 'encrypt' "
-                             "or 'decrypt'"))
+            raise ValueError("keyword 'algorithm' must be either 'encrypt' "
+                             "or 'decrypt'")
 
     def __repr__(self):
         r"""
@@ -981,8 +981,8 @@ def encrypt(self, plain, key, format='hex'):
             key_state = self._bin_to_GF(key)
             roundKeys = self.expand_key(key_state)
         else:
-            raise ValueError(("'format' keyword must be either 'hex' or "
-                             "'binary'"))
+            raise ValueError("'format' keyword must be either 'hex' or "
+                             "'binary'")
 
         state = self.add_round_key(state, roundKeys[0])
         for r in range(self._Nr-1):
@@ -1057,8 +1057,8 @@ def decrypt(self, ciphertext, key, format='hex'):
         elif format == 'binary':
             if not isinstance(ciphertext, str) or \
                any(c not in '01' for c in ciphertext):
-                raise TypeError(("'ciphertext' keyword must be a binary "
-                                 "string"))
+                raise TypeError("'ciphertext' keyword must be a binary "
+                                 "string")
             if len(ciphertext) != 32 * self._Nb:
                 msg = "'ciphertext' keyword's length must be {0}, not {1}"
                 raise ValueError(msg.format(32 * self._Nb, len(ciphertext)))
@@ -1072,8 +1072,8 @@ def decrypt(self, ciphertext, key, format='hex'):
             key_state = self._bin_to_GF(key)
             roundKeys = self.expand_key(key_state)
         else:
-            raise ValueError(("'format' keyword must be either \'hex\' or "
-                             "'binary'"))
+            raise ValueError("'format' keyword must be either \'hex\' or "
+                             "'binary'")
 
         state = self.add_round_key(state, roundKeys[self._Nr])
         state = self.shift_rows(state, algorithm='decrypt')
@@ -1874,8 +1874,8 @@ def _sub_bytes_pc(self, row, col, algorithm='encrypt', no_inversion=False):
             else:
                 return result ** 254
         else:
-            raise ValueError(("keyword 'algorithm' must be either 'encrypt' "
-                             "or 'decrypt'"))
+            raise ValueError("keyword 'algorithm' must be either 'encrypt' "
+                             "or 'decrypt'")
 
     def _srd(self, el, algorithm='encrypt'):
         r"""
@@ -1910,8 +1910,8 @@ def _srd(self, el, algorithm='encrypt'):
             state = [el] + [self._F.zero()]*((4 * self._Nb)-1)
             return p(state) ** 254
         else:
-            raise ValueError(("keyword 'algorithm' must be either 'encrypt' "
-                             "or 'decrypt'"))
+            raise ValueError("keyword 'algorithm' must be either 'encrypt' "
+                             "or 'decrypt'")
 
     def sub_bytes(self, state, algorithm='encrypt'):
         r"""
@@ -2010,8 +2010,8 @@ def _mix_columns_pc(self, row, col, algorithm='encrypt'):
         elif algorithm == 'decrypt':
             coeffs = self._mixcols_D
         else:
-            raise ValueError(("keyword 'algorithm' must be either 'encrypt' "
-                             "or 'decrypt'"))
+            raise ValueError("keyword 'algorithm' must be either 'encrypt' "
+                             "or 'decrypt'")
         return sum([coeffs[row,k] * self.state_vrs[k,col] for k in range(4)])
 
     def mix_columns(self, state, algorithm='encrypt'):
@@ -2109,8 +2109,8 @@ def _shift_rows_pc(self, row, col, algorithm='encrypt'):
         elif algorithm == 'decrypt':
             offs = self._shiftrows_offsets_D
         else:
-            raise ValueError(("keyword 'algorithm' must be either 'encrypt' "
-                             "or 'decrypt'"))
+            raise ValueError("keyword 'algorithm' must be either 'encrypt' "
+                             "or 'decrypt'")
         return self.state_vrs[row, (col + offs[4 - self._Nb][row]) % 4]
 
     def shift_rows(self, state, algorithm='encrypt'):

src/sage/data_structures/stream.py

@@ -107,7 +107,7 @@
 lazy_import('sage.combinat.sf.sfa', ['_variables_recursive', '_raise_variables'])
 
 
-class Stream():
+class Stream:
     """
     Abstract base class for all streams.
 
@@ -2410,7 +2410,7 @@ def stretched_power_restrict_degree(self, i, m, d):
                          _raise_variables(c, i, self._degree_one)
                          for mon, c in power_d}
             else:
-                terms = {tuple((mu.stretch(i) for mu in mon)):
+                terms = {tuple(mu.stretch(i) for mu in mon):
                          _raise_variables(c, i, self._degree_one)
                          for mon, c in power_d}
             return self._basis(self._p.element_class(self._p, terms))

src/sage/databases/cremona.py

@@ -1122,10 +1122,10 @@ def iter_optimal(self, conductors):
             if N == 990:
                 for c in self.__connection__.cursor().execute('SELECT class '
                     + 'FROM t_class WHERE conductor=990'):
-                    if c[0][-1] == u'h':
-                        yield self.elliptic_curve(c[0]+u'3')
+                    if c[0][-1] == 'h':
+                        yield self.elliptic_curve(c[0]+'3')
                     else:
-                        yield self.elliptic_curve(c[0]+u'1')
+                        yield self.elliptic_curve(c[0]+'1')
                 continue
             for c in self.__connection__.cursor().execute('SELECT curve '
                 + 'FROM t_curve,t_class USING(class) WHERE curve=class||1 '

src/sage/databases/findstat.py

@@ -4352,7 +4352,7 @@ def first_terms(self, function, level=None):
                 g = (x for x in self._sageconstructor_overridden
                      if self.element_level(x) == level)
 
-        return lazy_list(((x, function(x)) for x in g))
+        return lazy_list((x, function(x)) for x in g)
 
     def id(self):
         r"""

src/sage/databases/sql_db.py

@@ -254,7 +254,7 @@ def construct_skeleton(database):
         exe1 = cur.execute("PRAGMA table_info(%s)" % table[0])
         for col in exe1.fetchall():
             if not col[2]:
-                typ = u'NOTYPE'
+                typ = 'NOTYPE'
             else:
                 typ = col[2]
             skeleton[table[0]][col[1]] = {'sql':typ,
@@ -482,7 +482,7 @@ def __init__(self, database, *args, **kwds):
         else:
             self.__query_string__ = kwds['query_string']
             if 'param_tuple' in kwds:
-                self.__param_tuple__ = tuple((str(x) for x in kwds['param_tuple']))
+                self.__param_tuple__ = tuple(str(x) for x in kwds['param_tuple'])
             else:
                 self.__param_tuple__ = tuple()
             return
@@ -2164,7 +2164,7 @@ def add_rows(self, table_name, rows, entry_order=None):
         if self.__read_only__:
             raise RuntimeError('Cannot add rows to read only database.')
         quest = '(' + ', '.join('?' for i in rows[0]) + ')'
-        strows = [tuple((str(entry) for entry in row)) for row in rows]
+        strows = [tuple(str(entry) for entry in row) for row in rows]
 
         if entry_order is not None:
             self.__connection__.executemany('INSERT INTO ' + table_name

src/sage/doctest/control.py

@@ -341,7 +341,7 @@ def skipfile(filename, tested_optional_tags=False, *,
     return False
 
 
-class Logger():
+class Logger:
     r"""
     File-like object which implements writing to multiple files at
     once.

src/sage/doctest/external.py

@@ -379,7 +379,7 @@ def external_software() -> list[str]:
 external_software = external_software()
 
 
-class AvailableSoftware():
+class AvailableSoftware:
     """
     This class keeps the set of available software whose availability is detected lazily
     from the list of external software.

src/sage/doctest/fixtures.py

@@ -112,7 +112,7 @@ def sorted_pairs(iterable, pairs=False):
     return repr(val)
 
 
-class AttributeAccessTracerHelper():
+class AttributeAccessTracerHelper:
 
     def __init__(self, delegate, prefix="  ", reads=True):
         r"""
@@ -223,7 +223,7 @@ def set(self, name, val):
         setattr(self.delegate, name, val)
 
 
-class AttributeAccessTracerProxy():
+class AttributeAccessTracerProxy:
 
     def __init__(self, delegate, **kwds):
         r"""

src/sage/doctest/forker.py

@@ -2476,7 +2476,7 @@ def kill(self):
         return True
 
 
-class DocTestTask():
+class DocTestTask:
     """
     This class encapsulates the tests from a single source.
 

src/sage/doctest/parsing.py

@@ -652,7 +652,7 @@ def reduce_hex(fingerprints):
     return "%032x" % res
 
 
-class OriginalSource():
+class OriginalSource:
     r"""
     Context swapping out the pre-parsed source with the original for
     better reporting.

src/sage/doctest/sources.py

@@ -124,7 +124,7 @@ def get_basename(path):
     return basename
 
 
-class DocTestSource():
+class DocTestSource:
     """
     This class provides a common base class for different sources of doctests.
 

src/sage/dynamics/arithmetic_dynamics/berkovich_ds.py

@@ -869,7 +869,7 @@ def __call__(self, x, type_3_pole_check=True):
                     else:
                         new_poly.append(ring_of_integers(i).mod(ideal))
                 new_poly = R(new_poly)
-                fraction.append((new_poly))
+                fraction.append(new_poly)
             gcd = fraction[0].gcd(fraction[1])
             num = fraction[0].quo_rem(gcd)[0]
             dem = fraction[1].quo_rem(gcd)[0]

src/sage/dynamics/cellular_automata/glca.py

@@ -363,24 +363,24 @@ def _unicode_art_(self, number=None):
             number = len(self._states)
 
         space = len(self._states[:number]) * 2 - 1
-        ret = UnicodeArt([u' '*space + u'◾'])
+        ret = UnicodeArt([' '*space + '◾'])
         space += 1
         for i,state in enumerate(self._states[:number]):
-            temp = u' '*(space-2)
-            last = u' '
+            temp = ' '*(space-2)
+            last = ' '
             for x in state:
                 if x & 0x4:
-                    if last == u'╱':
-                        temp += u'╳'
+                    if last == '╱':
+                        temp += '╳'
                     else:
-                        temp += u'╲'
+                        temp += '╲'
                 else:
                     temp += last
-                temp += u'│' if x & 0x2 else ' '
-                last = u'╱' if x & 0x1 else ' '
+                temp += '│' if x & 0x2 else ' '
+                last = '╱' if x & 0x1 else ' '
             ret *= UnicodeArt([temp + last])
             space -= 1
-            ret *= UnicodeArt([u' '*space + u' '.join(u'◾' for dummy in range(2*i+1))])
+            ret *= UnicodeArt([' '*space + ' '.join('◾' for dummy in range(2*i+1))])
             space -= 1
         return ret
 

src/sage/dynamics/complex_dynamics/mandel_julia.py

@@ -430,6 +430,7 @@ def external_ray(theta, **kwds):
                 pixel[int(k[0]), int(k[1])] = tuple(ray_color)
     return M
 
+
 def kneading_sequence(theta):
     r"""
     Determines the kneading sequence for an angle theta in RR/ZZ which

src/sage/env.py

@@ -337,7 +337,7 @@ def get_cblas_pc_module_name() -> str:
     """
     import pkgconfig
     cblas_pc_modules = CBLAS_PC_MODULES.split(':')
-    return next((blas_lib for blas_lib in cblas_pc_modules if pkgconfig.exists(blas_lib)))
+    return next(blas_lib for blas_lib in cblas_pc_modules if pkgconfig.exists(blas_lib))
 
 
 default_required_modules = ('fflas-ffpack', 'givaro', 'gsl', 'linbox', 'Singular',

src/sage/features/__init__.py

@@ -467,7 +467,7 @@ def __str__(self):
         return "\n".join(lines)
 
 
-class FeatureTestResult():
+class FeatureTestResult:
     r"""
     The result of a :meth:`Feature.is_present` call.