pylint: enable the set_membership plugin

Which adds the `use-set-for-membership` check. It's generally faster in
python to use a set with the `in` keyword, because it's a hash check
instead of a linear walk, this is especially true with strings, where
it's actually O(n^2), one loop over the container, and an inner loop of
the strings (as string comparison works by checking that `a[n] == b[n]`,
in a loop).

Also, I'm tired of complaining about this in reviews, let the tools do
it for me :)

33 files changed, 62 insertions, 63 deletions

diff --git a/mesonbuild/ast/introspection.py b/mesonbuild/ast/introspection.py
index 765e49b..722c908 100644
--- a/mesonbuild/ast/introspection.py
+++ b/mesonbuild/ast/introspection.py
@@ -261,7 +261,7 @@ class IntrospectionInterpreter(AstInterpreter):
         extraf_nodes = traverse_nodes(extra_queue)
 
         # Make sure nothing can crash when creating the build class
-        kwargs_reduced = {k: v for k, v in kwargs.items() if k in targetclass.known_kwargs and k in ['install', 'build_by_default', 'build_always']}
+        kwargs_reduced = {k: v for k, v in kwargs.items() if k in targetclass.known_kwargs and k in {'install', 'build_by_default', 'build_always'}}
         kwargs_reduced = {k: v.value if isinstance(v, ElementaryNode) else v for k, v in kwargs_reduced.items()}
         kwargs_reduced = {k: v for k, v in kwargs_reduced.items() if not isinstance(v, BaseNode)}
         for_machine = MachineChoice.HOST
diff --git a/mesonbuild/backend/ninjabackend.py b/mesonbuild/backend/ninjabackend.py
index 7f47823..339867d 100644
--- a/mesonbuild/backend/ninjabackend.py
+++ b/mesonbuild/backend/ninjabackend.py
@@ -3535,7 +3535,7 @@ def _scan_fortran_file_deps(src: Path, srcdir: Path, dirname: Path, tdeps, compi
                 submodmatch = submodre.match(line)
                 if submodmatch is not None:
                     parents = submodmatch.group(1).lower().split(':')
-                    assert len(parents) in (1, 2), (
+                    assert len(parents) in {1, 2}, (
                         'submodule ancestry must be specified as'
                         f' ancestor:parent but Meson found {parents}')
 
diff --git a/mesonbuild/backend/vs2010backend.py b/mesonbuild/backend/vs2010backend.py
index 486c1a9..20cff56 100644
--- a/mesonbuild/backend/vs2010backend.py
+++ b/mesonbuild/backend/vs2010backend.py
@@ -852,13 +852,13 @@ class Vs2010Backend(backends.Backend):
 
     def _get_cl_compiler(self, target):
         for lang, c in target.compilers.items():
-            if lang in ('c', 'cpp'):
+            if lang in {'c', 'cpp'}:
                 return c
         # No source files, only objects, but we still need a compiler, so
         # return a found compiler
         if len(target.objects) > 0:
             for lang, c in self.environment.coredata.compilers[target.for_machine].items():
-                if lang in ('c', 'cpp'):
+                if lang in {'c', 'cpp'}:
                     return c
         raise MesonException('Could not find a C or C++ compiler. MSVC can only build C/C++ projects.')
 
diff --git a/mesonbuild/build.py b/mesonbuild/build.py
index 426ee26..0ef5122 100644
--- a/mesonbuild/build.py
+++ b/mesonbuild/build.py
@@ -1829,8 +1829,8 @@ class Executable(BuildTarget):
                 self.suffix = 'abs'
             elif ('c' in self.compilers and self.compilers['c'].get_id().startswith('xc16')):
                 self.suffix = 'elf'
-            elif ('c' in self.compilers and self.compilers['c'].get_id() in ('ti', 'c2000') or
-                  'cpp' in self.compilers and self.compilers['cpp'].get_id() in ('ti', 'c2000')):
+            elif ('c' in self.compilers and self.compilers['c'].get_id() in {'ti', 'c2000'} or
+                  'cpp' in self.compilers and self.compilers['cpp'].get_id() in {'ti', 'c2000'}):
                 self.suffix = 'out'
             else:
                 self.suffix = machine.get_exe_suffix()
@@ -2176,10 +2176,10 @@ class SharedLibrary(BuildTarget):
                     raise InvalidArguments('Shared library darwin_versions: must be X.Y.Z where '
                                            'X, Y, Z are numbers, and Y and Z are optional')
                 parts = v.split('.')
-                if len(parts) in (1, 2, 3) and int(parts[0]) > 65535:
+                if len(parts) in {1, 2, 3} and int(parts[0]) > 65535:
                     raise InvalidArguments('Shared library darwin_versions: must be X.Y.Z '
                                            'where X is [0, 65535] and Y, Z are optional')
-                if len(parts) in (2, 3) and int(parts[1]) > 255:
+                if len(parts) in {2, 3} and int(parts[1]) > 255:
                     raise InvalidArguments('Shared library darwin_versions: must be X.Y.Z '
                                            'where Y is [0, 255] and Y, Z are optional')
                 if len(parts) == 3 and int(parts[2]) > 255:
diff --git a/mesonbuild/cmake/common.py b/mesonbuild/cmake/common.py
index 85598da..dffdbdf 100644
--- a/mesonbuild/cmake/common.py
+++ b/mesonbuild/cmake/common.py
@@ -100,9 +100,9 @@ def _flags_to_list(raw: str) -> T.List[str]:
             escape = False
         elif i == '\\':
             escape = True
-        elif i in ['"', "'"]:
+        elif i in {'"', "'"}:
             in_string = not in_string
-        elif i in [' ', '\n']:
+        elif i in {' ', '\n'}:
             if in_string:
                 curr += i
             else:
diff --git a/mesonbuild/cmake/generator.py b/mesonbuild/cmake/generator.py
index d7a281a..9c9fa1c 100644
--- a/mesonbuild/cmake/generator.py
+++ b/mesonbuild/cmake/generator.py
@@ -99,7 +99,7 @@ def parse_generator_expressions(
 
     supported = {
         # Boolean functions
-        'BOOL': lambda x: '0' if x.upper() in ['0', 'FALSE', 'OFF', 'N', 'NO', 'IGNORE', 'NOTFOUND'] or x.endswith('-NOTFOUND') else '1',
+        'BOOL': lambda x: '0' if x.upper() in {'0', 'FALSE', 'OFF', 'N', 'NO', 'IGNORE', 'NOTFOUND'} or x.endswith('-NOTFOUND') else '1',
         'AND': lambda x: '1' if all(y == '1' for y in x.split(',')) else '0',
         'OR': lambda x: '1' if any(y == '1' for y in x.split(',')) else '0',
         'NOT': lambda x: '0' if x == '1' else '1',
diff --git a/mesonbuild/cmake/interpreter.py b/mesonbuild/cmake/interpreter.py
index f96333a..f453aa3 100644
--- a/mesonbuild/cmake/interpreter.py
+++ b/mesonbuild/cmake/interpreter.py
@@ -320,7 +320,7 @@ class ConverterTarget:
                         )
                         continue
                     self.override_options += [f'{i}_std={std}']
-                elif j in ['-fPIC', '-fpic', '-fPIE', '-fpie']:
+                elif j in {'-fPIC', '-fpic', '-fPIE', '-fpie'}:
                     self.pie = True
                 elif isinstance(ctgt, ConverterCustomTarget):
                     # Sometimes projects pass generated source files as compiler
@@ -1173,10 +1173,10 @@ class CMakeInterpreter:
                 src_node = assign(src_var, function('files', sources))
                 tgt_node = assign(tgt_var, function(tgt_func, [tgt_var, id_node(src_var), *generated], tgt_kwargs))
                 node_list += [src_node, tgt_node]
-                if tgt_func in ['static_library', 'shared_library']:
+                if tgt_func in {'static_library', 'shared_library'}:
                     dep_node = assign(dep_var, function('declare_dependency', kwargs=dep_kwargs))
                     node_list += [dep_node]
-                elif tgt_func in ['shared_module']:
+                elif tgt_func == 'shared_module':
                     del dep_kwargs['link_with']
                     dep_node = assign(dep_var, function('declare_dependency', kwargs=dep_kwargs))
                     node_list += [dep_node]
diff --git a/mesonbuild/cmake/traceparser.py b/mesonbuild/cmake/traceparser.py
index ef8ea39..e5aea8e 100644
--- a/mesonbuild/cmake/traceparser.py
+++ b/mesonbuild/cmake/traceparser.py
@@ -682,14 +682,14 @@ class CMakeTraceParser:
             if i in ignore:
                 continue
 
-            if i in ['INTERFACE', 'LINK_INTERFACE_LIBRARIES', 'PUBLIC', 'PRIVATE', 'LINK_PUBLIC', 'LINK_PRIVATE']:
+            if i in {'INTERFACE', 'LINK_INTERFACE_LIBRARIES', 'PUBLIC', 'PRIVATE', 'LINK_PUBLIC', 'LINK_PRIVATE'}:
                 mode = i
                 continue
 
-            if mode in ['INTERFACE', 'LINK_INTERFACE_LIBRARIES', 'PUBLIC', 'LINK_PUBLIC']:
+            if mode in {'INTERFACE', 'LINK_INTERFACE_LIBRARIES', 'PUBLIC', 'LINK_PUBLIC'}:
                 interface += i.split(';')
 
-            if mode in ['PUBLIC', 'PRIVATE', 'LINK_PRIVATE']:
+            if mode in {'PUBLIC', 'PRIVATE', 'LINK_PRIVATE'}:
                 private += i.split(';')
 
         if paths:
diff --git a/mesonbuild/compilers/cuda.py b/mesonbuild/compilers/cuda.py
index 46a86b7..25a7baf 100644
--- a/mesonbuild/compilers/cuda.py
+++ b/mesonbuild/compilers/cuda.py
@@ -747,7 +747,7 @@ class CudaCompiler(Compiler):
         # native option to override it; override it with /NODEFAULTLIB
         host_link_arg_overrides = []
         host_crt_compile_args = self.host_compiler.get_crt_compile_args(crt_val, buildtype)
-        if any(arg in ['/MDd', '/MD', '/MTd'] for arg in host_crt_compile_args):
+        if any(arg in {'/MDd', '/MD', '/MTd'} for arg in host_crt_compile_args):
             host_link_arg_overrides += ['/NODEFAULTLIB:LIBCMT.lib']
         return self._to_host_flags(host_link_arg_overrides + self.host_compiler.get_crt_link_args(crt_val, buildtype), _Phase.LINKER)
 
diff --git a/mesonbuild/compilers/d.py b/mesonbuild/compilers/d.py
index cd67d5a..90c0498 100644
--- a/mesonbuild/compilers/d.py
+++ b/mesonbuild/compilers/d.py
@@ -463,7 +463,7 @@ class DmdLikeCompilerMixin(CompilerMixinBase):
 
         if crt_val in self.mscrt_args:
             return self.mscrt_args[crt_val]
-        assert crt_val in ['from_buildtype', 'static_from_buildtype']
+        assert crt_val in {'from_buildtype', 'static_from_buildtype'}
 
         dbg = 'mdd'
         rel = 'md'
diff --git a/mesonbuild/compilers/fortran.py b/mesonbuild/compilers/fortran.py
index b82b2ff..90ca010 100644
--- a/mesonbuild/compilers/fortran.py
+++ b/mesonbuild/compilers/fortran.py
@@ -105,9 +105,9 @@ class FortranCompiler(CLikeCompiler, Compiler):
     def module_name_to_filename(self, module_name: str) -> str:
         if '_' in module_name:  # submodule
             s = module_name.lower()
-            if self.id in ('gcc', 'intel', 'intel-cl'):
+            if self.id in {'gcc', 'intel', 'intel-cl'}:
                 filename = s.replace('_', '@') + '.smod'
-            elif self.id in ('pgi', 'flang'):
+            elif self.id in {'pgi', 'flang'}:
                 filename = s.replace('_', '-') + '.mod'
             else:
                 filename = s + '.mod'
diff --git a/mesonbuild/compilers/java.py b/mesonbuild/compilers/java.py
index bfd9b1a..ebae509 100644
--- a/mesonbuild/compilers/java.py
+++ b/mesonbuild/compilers/java.py
@@ -75,7 +75,7 @@ class JavaCompiler(BasicLinkerIsCompilerMixin, Compiler):
     def compute_parameters_with_absolute_paths(self, parameter_list: T.List[str],
                                                build_dir: str) -> T.List[str]:
         for idx, i in enumerate(parameter_list):
-            if i in ['-cp', '-classpath', '-sourcepath'] and idx + 1 < len(parameter_list):
+            if i in {'-cp', '-classpath', '-sourcepath'} and idx + 1 < len(parameter_list):
                 path_list = parameter_list[idx + 1].split(os.pathsep)
                 path_list = [os.path.normpath(os.path.join(build_dir, x)) for x in path_list]
                 parameter_list[idx + 1] = os.pathsep.join(path_list)
diff --git a/mesonbuild/compilers/mixins/clike.py b/mesonbuild/compilers/mixins/clike.py
index b4824d5..8736c6d 100644
--- a/mesonbuild/compilers/mixins/clike.py
+++ b/mesonbuild/compilers/mixins/clike.py
@@ -1320,7 +1320,7 @@ class CLikeCompiler(Compiler):
         # don't work
         m = env.machines[self.for_machine]
         if not (m.is_windows() or m.is_cygwin()):
-            if name in ['dllimport', 'dllexport']:
+            if name in {'dllimport', 'dllexport'}:
                 return False, False
 
         return self.compiles(self.attribute_check_func(name), env,
diff --git a/mesonbuild/compilers/mixins/visualstudio.py b/mesonbuild/compilers/mixins/visualstudio.py
index d61ad42..765d63d 100644
--- a/mesonbuild/compilers/mixins/visualstudio.py
+++ b/mesonbuild/compilers/mixins/visualstudio.py
@@ -228,7 +228,7 @@ class VisualStudioLikeCompiler(Compiler, metaclass=abc.ABCMeta):
         for i in args:
             # -mms-bitfields is specific to MinGW-GCC
             # -pthread is only valid for GCC
-            if i in ('-mms-bitfields', '-pthread'):
+            if i in {'-mms-bitfields', '-pthread'}:
                 continue
             if i.startswith('-LIBPATH:'):
                 i = '/LIBPATH:' + i[9:]
@@ -361,7 +361,7 @@ class VisualStudioLikeCompiler(Compiler, metaclass=abc.ABCMeta):
     def get_crt_compile_args(self, crt_val: str, buildtype: str) -> T.List[str]:
         if crt_val in self.crt_args:
             return self.crt_args[crt_val]
-        assert crt_val in ['from_buildtype', 'static_from_buildtype']
+        assert crt_val in {'from_buildtype', 'static_from_buildtype'}
         dbg = 'mdd'
         rel = 'md'
         if crt_val == 'static_from_buildtype':
@@ -385,7 +385,7 @@ class VisualStudioLikeCompiler(Compiler, metaclass=abc.ABCMeta):
     def has_func_attribute(self, name: str, env: 'Environment') -> T.Tuple[bool, bool]:
         # MSVC doesn't have __attribute__ like Clang and GCC do, so just return
         # false without compiling anything
-        return name in ['dllimport', 'dllexport'], False
+        return name in {'dllimport', 'dllexport'}, False
 
     def get_argument_syntax(self) -> str:
         return 'msvc'
diff --git a/mesonbuild/dependencies/base.py b/mesonbuild/dependencies/base.py
index e78a420..d826026 100644
--- a/mesonbuild/dependencies/base.py
+++ b/mesonbuild/dependencies/base.py
@@ -274,7 +274,7 @@ class InternalDependency(Dependency):
         assert isinstance(result, InternalDependency)
         memo[id(self)] = result
         for k, v in self.__dict__.items():
-            if k in ['libraries', 'whole_libraries']:
+            if k in {'libraries', 'whole_libraries'}:
                 setattr(result, k, copy.copy(v))
             else:
                 setattr(result, k, copy.deepcopy(v, memo))
diff --git a/mesonbuild/dependencies/boost.py b/mesonbuild/dependencies/boost.py
index 2a901ce..4ebd88d 100644
--- a/mesonbuild/dependencies/boost.py
+++ b/mesonbuild/dependencies/boost.py
@@ -152,9 +152,9 @@ class BoostLibraryFile():
             self.version_lib = '{}_{}'.format(self.vers_raw[0], self.vers_raw[1])
 
         # Detecting library type
-        if self.nvsuffix in ['so', 'dll', 'dll.a', 'dll.lib', 'dylib']:
+        if self.nvsuffix in {'so', 'dll', 'dll.a', 'dll.lib', 'dylib'}:
             self.static = False
-        elif self.nvsuffix in ['a', 'lib']:
+        elif self.nvsuffix in {'a', 'lib'}:
             self.static = True
         else:
             raise UnknownFileException(self.path)
@@ -177,7 +177,7 @@ class BoostLibraryFile():
         for i in tags:
             if i == 'mt':
                 self.mt = True
-            elif len(i) == 3 and i[1:] in ['32', '64']:
+            elif len(i) == 3 and i[1:] in {'32', '64'}:
                 self.arch = i
             elif BoostLibraryFile.reg_abi_tag.match(i):
                 self.runtime_static = 's' in i
@@ -316,13 +316,13 @@ class BoostLibraryFile():
         # If no vscrt tag present, assume that it fits  ['/MD', '/MDd', '/MT', '/MTd']
         if not vscrt:
             return True
-        if vscrt in ['/MD', '-MD']:
+        if vscrt in {'/MD', '-MD'}:
             return not self.runtime_static and not self.runtime_debug
-        elif vscrt in ['/MDd', '-MDd']:
+        elif vscrt in {'/MDd', '-MDd'}:
             return not self.runtime_static and self.runtime_debug
-        elif vscrt in ['/MT', '-MT']:
+        elif vscrt in {'/MT', '-MT'}:
             return (self.runtime_static or not self.static) and not self.runtime_debug
-        elif vscrt in ['/MTd', '-MTd']:
+        elif vscrt in {'/MTd', '-MTd'}:
             return (self.runtime_static or not self.static) and self.runtime_debug
 
         mlog.warning(f'Boost: unknown vscrt tag {vscrt}. This may cause the compilation to fail. Please consider reporting this as a bug.', once=True)
diff --git a/mesonbuild/dependencies/detect.py b/mesonbuild/dependencies/detect.py
index ebbcc2f..782c2f1 100644
--- a/mesonbuild/dependencies/detect.py
+++ b/mesonbuild/dependencies/detect.py
@@ -52,8 +52,8 @@ def get_dep_identifier(name: str, kwargs: T.Dict[str, T.Any]) -> 'TV_DepID':
         # 'default_options' is only used in fallback case
         # 'not_found_message' has no impact on the dependency lookup
         # 'include_type' is handled after the dependency lookup
-        if key in ('version', 'native', 'required', 'fallback', 'allow_fallback', 'default_options',
-                   'not_found_message', 'include_type'):
+        if key in {'version', 'native', 'required', 'fallback', 'allow_fallback', 'default_options',
+                   'not_found_message', 'include_type'}:
             continue
         # All keyword arguments are strings, ints, or lists (or lists of lists)
         if isinstance(value, list):
diff --git a/mesonbuild/dependencies/misc.py b/mesonbuild/dependencies/misc.py
index e5f92b3..d23eeee 100644
--- a/mesonbuild/dependencies/misc.py
+++ b/mesonbuild/dependencies/misc.py
@@ -214,7 +214,7 @@ class Python3DependencySystem(SystemDependency):
                 return None
         elif pyplat == 'win32':
             return '32'
-        elif pyplat in ('win64', 'win-amd64'):
+        elif pyplat in {'win64', 'win-amd64'}:
             return '64'
         mlog.log(f'Unknown Windows Python platform {pyplat!r}')
         return None
diff --git a/mesonbuild/dependencies/mpi.py b/mesonbuild/dependencies/mpi.py
index a99a4cc..842535d 100644
--- a/mesonbuild/dependencies/mpi.py
+++ b/mesonbuild/dependencies/mpi.py
@@ -136,7 +136,7 @@ class _MPIConfigToolDependency(ConfigToolDependency):
         for f in args:
             if self._is_link_arg(f):
                 result.append(f)
-                if f in ('-L', '-Xlinker'):
+                if f in {'-L', '-Xlinker'}:
                     include_next = True
             elif include_next:
                 include_next = False
diff --git a/mesonbuild/depfile.py b/mesonbuild/depfile.py
index 64b973f..912a817 100644
--- a/mesonbuild/depfile.py
+++ b/mesonbuild/depfile.py
@@ -36,7 +36,7 @@ def parse(lines: T.Iterable[str]) -> T.List[T.Tuple[T.List[str], T.List[str]]]:
             if c in {'\\', '$'}:
                 escape = c
                 continue
-            elif c in (' ', '\n'):
+            elif c in {' ', '\n'}:
                 if out != '':
                     if in_deps:
                         deps.append(out)
diff --git a/mesonbuild/environment.py b/mesonbuild/environment.py
index 40ce9d5..a9df75e 100644
--- a/mesonbuild/environment.py
+++ b/mesonbuild/environment.py
@@ -306,7 +306,7 @@ def detect_cpu_family(compilers: CompilersDict) -> str:
         trial = 'ppc64'
     elif trial.startswith(('powerpc', 'ppc')) or trial in {'macppc', 'power macintosh'}:
         trial = 'ppc'
-    elif trial in ('amd64', 'x64', 'i86pc'):
+    elif trial in {'amd64', 'x64', 'i86pc'}:
         trial = 'x86_64'
     elif trial in {'sun4u', 'sun4v'}:
         trial = 'sparc64'
@@ -353,7 +353,7 @@ def detect_cpu(compilers: CompilersDict) -> str:
     else:
         trial = platform.machine().lower()
 
-    if trial in ('amd64', 'x64', 'i86pc'):
+    if trial in {'amd64', 'x64', 'i86pc'}:
         trial = 'x86_64'
     if trial == 'x86_64':
         # Same check as above for cpu_family
diff --git a/mesonbuild/mesonmain.py b/mesonbuild/mesonmain.py
index c276dab..ca38f29 100644
--- a/mesonbuild/mesonmain.py
+++ b/mesonbuild/mesonmain.py
@@ -160,7 +160,6 @@ class CommandLineParser:
 
     def run(self, args):
         implicit_setup_command_notice = False
-        pending_python_deprecation_notice = False
         # If first arg is not a known command, assume user wants to run the setup
         # command.
         known_commands = list(self.commands.keys()) + ['-h', '--help']
@@ -187,8 +186,8 @@ class CommandLineParser:
         # Bump the version here in order to add a pre-exit warning that we are phasing out
         # support for old python. If this is already the oldest supported version, then
         # this can never be true and does nothing.
-        if command in ('setup', 'compile', 'test', 'install') and sys.version_info < (3, 7):
-            pending_python_deprecation_notice = True
+        pending_python_deprecation_notice = \
+            command in {'setup', 'compile', 'test', 'install'} and sys.version_info < (3, 7)
 
         try:
             return options.run_func(options)
diff --git a/mesonbuild/minit.py b/mesonbuild/minit.py
index e923582..1897950 100644
--- a/mesonbuild/minit.py
+++ b/mesonbuild/minit.py
@@ -104,7 +104,7 @@ def autodetect_options(options: 'argparse.Namespace', sample: bool = False) -> N
             if f.suffix == '.c':
                 options.language = 'c'
                 break
-            if f.suffix in ('.cc', '.cpp'):
+            if f.suffix in {'.cc', '.cpp'}:
                 options.language = 'cpp'
                 break
             if f.suffix == '.cs':
diff --git a/mesonbuild/modules/__init__.py b/mesonbuild/modules/__init__.py
index a83e9da..e2ed38c 100644
--- a/mesonbuild/modules/__init__.py
+++ b/mesonbuild/modules/__init__.py
@@ -237,7 +237,7 @@ def is_module_library(fname):
     if hasattr(fname, 'fname'):
         fname = fname.fname
     suffix = fname.split('.')[-1]
-    return suffix in ('gir', 'typelib')
+    return suffix in {'gir', 'typelib'}
 
 
 class ModuleReturnValue:
diff --git a/mesonbuild/modules/gnome.py b/mesonbuild/modules/gnome.py
index f0ef03c..1d5e746 100644
--- a/mesonbuild/modules/gnome.py
+++ b/mesonbuild/modules/gnome.py
@@ -874,7 +874,7 @@ class GnomeModule(ExtensionModule):
         for girtarget in girtargets:
             for lang, compiler in girtarget.compilers.items():
                 # XXX: Can you use g-i with any other language?
-                if lang in ('c', 'cpp', 'objc', 'objcpp', 'd'):
+                if lang in {'c', 'cpp', 'objc', 'objcpp', 'd'}:
                     ret.append((lang, compiler))
                     break
 
diff --git a/mesonbuild/modules/python.py b/mesonbuild/modules/python.py
index 71a25d5..6bbfdb9 100644
--- a/mesonbuild/modules/python.py
+++ b/mesonbuild/modules/python.py
@@ -194,7 +194,7 @@ class PythonSystemDependency(SystemDependency, _PythonDependencyBase):
                 return None
         elif self.platform == 'win32':
             return '32'
-        elif self.platform in ('win64', 'win-amd64'):
+        elif self.platform in {'win64', 'win-amd64'}:
             return '64'
         mlog.log(f'Unknown Windows Python platform {self.platform!r}')
         return None
@@ -727,7 +727,7 @@ class PythonModule(ExtensionModule):
             # on various platforms, let's not give up just yet, if an executable
             # named python is available and has a compatible version, let's use
             # it
-            if not python.found() and name_or_path in ['python2', 'python3']:
+            if not python.found() and name_or_path in {'python2', 'python3'}:
                 python = PythonExternalProgram('python')
 
         if python.found():
diff --git a/mesonbuild/munstable_coredata.py b/mesonbuild/munstable_coredata.py
index 49e0530..fa3b720 100644
--- a/mesonbuild/munstable_coredata.py
+++ b/mesonbuild/munstable_coredata.py
@@ -61,17 +61,17 @@ def run(options):
     coredata = cdata.load(options.builddir)
     backend = coredata.get_option(OptionKey('backend'))
     for k, v in sorted(coredata.__dict__.items()):
-        if k in ('backend_options', 'base_options', 'builtins', 'compiler_options', 'user_options'):
+        if k in {'backend_options', 'base_options', 'builtins', 'compiler_options', 'user_options'}:
             # use `meson configure` to view these
             pass
-        elif k in ['install_guid', 'test_guid', 'regen_guid']:
+        elif k in {'install_guid', 'test_guid', 'regen_guid'}:
             if all_backends or backend.startswith('vs'):
                 print(k + ': ' + v)
         elif k == 'target_guids':
             if all_backends or backend.startswith('vs'):
                 print(k + ':')
                 dump_guids(v)
-        elif k in ['lang_guids']:
+        elif k == 'lang_guids':
             if all_backends or backend.startswith('vs') or backend == 'xcode':
                 print(k + ':')
                 dump_guids(v)
diff --git a/mesonbuild/rewriter.py b/mesonbuild/rewriter.py
index 7d4f989..8a1021c 100644
--- a/mesonbuild/rewriter.py
+++ b/mesonbuild/rewriter.py
@@ -420,7 +420,7 @@ class Rewriter:
         if target in self.interpreter.assignments:
             node = self.interpreter.assignments[target]
             if isinstance(node, FunctionNode):
-                if node.func_name in ['executable', 'jar', 'library', 'shared_library', 'shared_module', 'static_library', 'both_libraries']:
+                if node.func_name in {'executable', 'jar', 'library', 'shared_library', 'shared_module', 'static_library', 'both_libraries'}:
                     tgt = self.interpreter.assign_vals[target]
 
         return tgt
@@ -440,7 +440,7 @@ class Rewriter:
         if dependency in self.interpreter.assignments:
             node = self.interpreter.assignments[dependency]
             if isinstance(node, FunctionNode):
-                if node.func_name in ['dependency']:
+                if node.func_name == 'dependency':
                     name = self.interpreter.flatten_args(node.args)[0]
                     dep = check_list(name)
 
@@ -952,15 +952,15 @@ class Rewriter:
                 while raw[end] != '=':
                     end += 1
                 end += 1 # Handle the '='
-                while raw[end] in [' ', '\n', '\t']:
+                while raw[end] in {' ', '\n', '\t'}:
                     end += 1
 
             files[i['file']]['raw'] = raw[:start] + i['str'] + raw[end:]
 
         for i in str_list:
-            if i['action'] in ['modify', 'rm']:
+            if i['action'] in {'modify', 'rm'}:
                 remove_node(i)
-            elif i['action'] in ['add']:
+            elif i['action'] == 'add':
                 files[i['file']]['raw'] += i['str'] + '\n'
 
         # Write the files back
diff --git a/mesonbuild/scripts/cmake_run_ctgt.py b/mesonbuild/scripts/cmake_run_ctgt.py
index dfb70d1..33e07d6 100755
--- a/mesonbuild/scripts/cmake_run_ctgt.py
+++ b/mesonbuild/scripts/cmake_run_ctgt.py
@@ -49,10 +49,10 @@ def run(argsv: T.List[str]) -> int:
         capture_file = ''
 
         for j in i:
-            if j in ['>', '>>']:
+            if j in {'>', '>>'}:
                 stdout = subprocess.PIPE
                 continue
-            elif j in ['&>', '&>>']:
+            elif j in {'&>', '&>>'}:
                 stdout = subprocess.PIPE
                 stderr = subprocess.STDOUT
                 continue
diff --git a/mesonbuild/scripts/symbolextractor.py b/mesonbuild/scripts/symbolextractor.py
index 565b467..393e66f 100644
--- a/mesonbuild/scripts/symbolextractor.py
+++ b/mesonbuild/scripts/symbolextractor.py
@@ -118,7 +118,7 @@ def gnu_syms(libfilename: str, outfilename: str) -> None:
         # Store the size of symbols pointing to data objects so we relink
         # when those change, which is needed because of copy relocations
         # https://github.com/mesonbuild/meson/pull/7132#issuecomment-628353702
-        if line_split[1].upper() in ('B', 'G', 'D') and len(line_split) >= 4:
+        if line_split[1].upper() in {'B', 'G', 'D'} and len(line_split) >= 4:
             entry += [line_split[3]]
         result += [' '.join(entry)]
     write_if_changed('\n'.join(result) + '\n', outfilename)
diff --git a/mesonbuild/scripts/tags.py b/mesonbuild/scripts/tags.py
index 9098efb..8f1706d 100644
--- a/mesonbuild/scripts/tags.py
+++ b/mesonbuild/scripts/tags.py
@@ -47,7 +47,7 @@ def run(args: T.List[str]) -> int:
     tool_name = args[0]
     srcdir_name = args[1]
     os.chdir(srcdir_name)
-    assert tool_name in ['cscope', 'ctags', 'etags']
+    assert tool_name in {'cscope', 'ctags', 'etags'}
     res = globals()[tool_name]()
     assert isinstance(res, int)
     return res
diff --git a/mesonbuild/utils/universal.py b/mesonbuild/utils/universal.py
index 4eafcd1..33c81c6 100644
--- a/mesonbuild/utils/universal.py
+++ b/mesonbuild/utils/universal.py
@@ -1002,7 +1002,7 @@ def get_library_dirs() -> T.List[str]:
         return unixdirs
     # FIXME: this needs to be further genericized for aarch64 etc.
     machine = platform.machine()
-    if machine in ('i386', 'i486', 'i586', 'i686'):
+    if machine in {'i386', 'i486', 'i586', 'i686'}:
         plat = 'i386'
     elif machine.startswith('arm'):
         plat = 'arm'
diff --git a/mesonbuild/wrap/wrap.py b/mesonbuild/wrap/wrap.py
index b1c2205..e8c955a 100644
--- a/mesonbuild/wrap/wrap.py
+++ b/mesonbuild/wrap/wrap.py
@@ -613,7 +613,7 @@ class Resolver:
 
     def is_git_full_commit_id(self, revno: str) -> bool:
         result = False
-        if len(revno) in (40, 64): # 40 for sha1, 64 for upcoming sha256
+        if len(revno) in {40, 64}: # 40 for sha1, 64 for upcoming sha256
             result = all(ch in '0123456789AaBbCcDdEeFf' for ch in revno)
         return result