diff --git a/libcxx/test/libcxx/experimental/lit.local.cfg b/libcxx/test/libcxx/experimental/lit.local.cfg
--- a/libcxx/test/libcxx/experimental/lit.local.cfg
+++ b/libcxx/test/libcxx/experimental/lit.local.cfg
@@ -1,3 +1,3 @@
 # Disable all of the experimental tests if the correct feature is not available.
-if 'c++experimental' not in config.available_features:
-  config.unsupported = True
+if "c++experimental" not in config.available_features:
+    config.unsupported = True
diff --git a/libcxx/test/libcxx/input.output/file.streams/lit.local.cfg b/libcxx/test/libcxx/input.output/file.streams/lit.local.cfg
--- a/libcxx/test/libcxx/input.output/file.streams/lit.local.cfg
+++ b/libcxx/test/libcxx/input.output/file.streams/lit.local.cfg
@@ -1,6 +1,7 @@
 # Load the same local configuration as the corresponding one in libcxx/test/std
 import os
-inLibcxx = os.path.join('libcxx', 'test', 'libcxx')
-inStd = os.path.join('libcxx', 'test', 'std')
+
+inLibcxx = os.path.join("libcxx", "test", "libcxx")
+inStd = os.path.join("libcxx", "test", "std")
 localConfig = os.path.normpath(os.path.realpath(__file__)).replace(inLibcxx, inStd)
 config.load_from_path(localConfig, lit_config)
diff --git a/libcxx/test/libcxx/input.output/filesystems/lit.local.cfg b/libcxx/test/libcxx/input.output/filesystems/lit.local.cfg
--- a/libcxx/test/libcxx/input.output/filesystems/lit.local.cfg
+++ b/libcxx/test/libcxx/input.output/filesystems/lit.local.cfg
@@ -1,4 +1,7 @@
 # Load the same local configuration as the filesystem tests in libcxx/test/std
 import os
-std_filesystem_tests = os.path.join(config.test_source_root, 'std', 'input.output', 'filesystems')
-config.load_from_path(os.path.join(std_filesystem_tests, 'lit.local.cfg'), lit_config)
+
+std_filesystem_tests = os.path.join(
+    config.test_source_root, "std", "input.output", "filesystems"
+)
+config.load_from_path(os.path.join(std_filesystem_tests, "lit.local.cfg"), lit_config)
diff --git a/libcxx/test/libcxx/input.output/iostream.format/lit.local.cfg b/libcxx/test/libcxx/input.output/iostream.format/lit.local.cfg
--- a/libcxx/test/libcxx/input.output/iostream.format/lit.local.cfg
+++ b/libcxx/test/libcxx/input.output/iostream.format/lit.local.cfg
@@ -1,6 +1,7 @@
 # Load the same local configuration as the corresponding one in libcxx/test/std
 import os
-inLibcxx = os.path.join('libcxx', 'test', 'libcxx')
-inStd = os.path.join('libcxx', 'test', 'std')
+
+inLibcxx = os.path.join("libcxx", "test", "libcxx")
+inStd = os.path.join("libcxx", "test", "std")
 localConfig = os.path.normpath(os.path.realpath(__file__)).replace(inLibcxx, inStd)
 config.load_from_path(localConfig, lit_config)
diff --git a/libcxx/test/libcxx/input.output/iostream.objects/lit.local.cfg b/libcxx/test/libcxx/input.output/iostream.objects/lit.local.cfg
--- a/libcxx/test/libcxx/input.output/iostream.objects/lit.local.cfg
+++ b/libcxx/test/libcxx/input.output/iostream.objects/lit.local.cfg
@@ -1,6 +1,7 @@
 # Load the same local configuration as the corresponding one in libcxx/test/std
 import os
-inLibcxx = os.path.join('libcxx', 'test', 'libcxx')
-inStd = os.path.join('libcxx', 'test', 'std')
+
+inLibcxx = os.path.join("libcxx", "test", "libcxx")
+inStd = os.path.join("libcxx", "test", "std")
 localConfig = os.path.normpath(os.path.realpath(__file__)).replace(inLibcxx, inStd)
 config.load_from_path(localConfig, lit_config)
diff --git a/libcxx/test/libcxx/input.output/iostreams.base/lit.local.cfg b/libcxx/test/libcxx/input.output/iostreams.base/lit.local.cfg
--- a/libcxx/test/libcxx/input.output/iostreams.base/lit.local.cfg
+++ b/libcxx/test/libcxx/input.output/iostreams.base/lit.local.cfg
@@ -1,6 +1,7 @@
 # Load the same local configuration as the corresponding one in libcxx/test/std
 import os
-inLibcxx = os.path.join('libcxx', 'test', 'libcxx')
-inStd = os.path.join('libcxx', 'test', 'std')
+
+inLibcxx = os.path.join("libcxx", "test", "libcxx")
+inStd = os.path.join("libcxx", "test", "std")
 localConfig = os.path.normpath(os.path.realpath(__file__)).replace(inLibcxx, inStd)
 config.load_from_path(localConfig, lit_config)
diff --git a/libcxx/test/libcxx/input.output/stream.buffers/lit.local.cfg b/libcxx/test/libcxx/input.output/stream.buffers/lit.local.cfg
--- a/libcxx/test/libcxx/input.output/stream.buffers/lit.local.cfg
+++ b/libcxx/test/libcxx/input.output/stream.buffers/lit.local.cfg
@@ -1,6 +1,7 @@
 # Load the same local configuration as the corresponding one in libcxx/test/std
 import os
-inLibcxx = os.path.join('libcxx', 'test', 'libcxx')
-inStd = os.path.join('libcxx', 'test', 'std')
+
+inLibcxx = os.path.join("libcxx", "test", "libcxx")
+inStd = os.path.join("libcxx", "test", "std")
 localConfig = os.path.normpath(os.path.realpath(__file__)).replace(inLibcxx, inStd)
 config.load_from_path(localConfig, lit_config)
diff --git a/libcxx/test/libcxx/input.output/string.streams/lit.local.cfg b/libcxx/test/libcxx/input.output/string.streams/lit.local.cfg
--- a/libcxx/test/libcxx/input.output/string.streams/lit.local.cfg
+++ b/libcxx/test/libcxx/input.output/string.streams/lit.local.cfg
@@ -1,6 +1,7 @@
 # Load the same local configuration as the corresponding one in libcxx/test/std
 import os
-inLibcxx = os.path.join('libcxx', 'test', 'libcxx')
-inStd = os.path.join('libcxx', 'test', 'std')
+
+inLibcxx = os.path.join("libcxx", "test", "libcxx")
+inStd = os.path.join("libcxx", "test", "std")
 localConfig = os.path.normpath(os.path.realpath(__file__)).replace(inLibcxx, inStd)
 config.load_from_path(localConfig, lit_config)
diff --git a/libcxx/test/libcxx/lit.local.cfg b/libcxx/test/libcxx/lit.local.cfg
--- a/libcxx/test/libcxx/lit.local.cfg
+++ b/libcxx/test/libcxx/lit.local.cfg
@@ -1,3 +1,4 @@
 # The tests in this directory need to run Python
 import pipes, sys
-config.substitutions.append(('%{python}', pipes.quote(sys.executable)))
+
+config.substitutions.append(("%{python}", pipes.quote(sys.executable)))
diff --git a/libcxx/test/libcxx/localization/lit.local.cfg b/libcxx/test/libcxx/localization/lit.local.cfg
--- a/libcxx/test/libcxx/localization/lit.local.cfg
+++ b/libcxx/test/libcxx/localization/lit.local.cfg
@@ -1,6 +1,7 @@
 # Load the same local configuration as the corresponding one in libcxx/test/std
 import os
-inLibcxx = os.path.join('libcxx', 'test', 'libcxx')
-inStd = os.path.join('libcxx', 'test', 'std')
+
+inLibcxx = os.path.join("libcxx", "test", "libcxx")
+inStd = os.path.join("libcxx", "test", "std")
 localConfig = os.path.normpath(os.path.realpath(__file__)).replace(inLibcxx, inStd)
 config.load_from_path(localConfig, lit_config)
diff --git a/libcxx/test/libcxx/selftest/additional_compile_flags/lit.local.cfg b/libcxx/test/libcxx/selftest/additional_compile_flags/lit.local.cfg
--- a/libcxx/test/libcxx/selftest/additional_compile_flags/lit.local.cfg
+++ b/libcxx/test/libcxx/selftest/additional_compile_flags/lit.local.cfg
@@ -1,2 +1,2 @@
 # Add a Lit feature so we can test conditional addition of compile flags.
-config.available_features.add('some-defined-feature')
+config.available_features.add("some-defined-feature")
diff --git a/libcxx/test/libcxx/selftest/dsl/lit.local.cfg b/libcxx/test/libcxx/selftest/dsl/lit.local.cfg
--- a/libcxx/test/libcxx/selftest/dsl/lit.local.cfg
+++ b/libcxx/test/libcxx/selftest/dsl/lit.local.cfg
@@ -9,6 +9,7 @@
 # to pass it to the test, and we decode and unpickle the substitutions from
 # within the test.
 import base64, lit.util, pickle
+
 base64Encode = lambda s: lit.util.to_string(base64.b64encode(lit.util.to_bytes(s)))
 escapedSubstitutions = base64Encode(pickle.dumps(config.substitutions))
-config.substitutions.append(('%{substitutions}', escapedSubstitutions))
+config.substitutions.append(("%{substitutions}", escapedSubstitutions))
diff --git a/libcxx/test/std/depr/depr.ios.members/lit.local.cfg b/libcxx/test/std/depr/depr.ios.members/lit.local.cfg
--- a/libcxx/test/std/depr/depr.ios.members/lit.local.cfg
+++ b/libcxx/test/std/depr/depr.ios.members/lit.local.cfg
@@ -1,2 +1,2 @@
-if 'no-localization' in config.available_features:
-  config.unsupported = True
+if "no-localization" in config.available_features:
+    config.unsupported = True
diff --git a/libcxx/test/std/depr/depr.str.strstreams/lit.local.cfg b/libcxx/test/std/depr/depr.str.strstreams/lit.local.cfg
--- a/libcxx/test/std/depr/depr.str.strstreams/lit.local.cfg
+++ b/libcxx/test/std/depr/depr.str.strstreams/lit.local.cfg
@@ -1,2 +1,2 @@
-if 'no-localization' in config.available_features:
-  config.unsupported = True
+if "no-localization" in config.available_features:
+    config.unsupported = True
diff --git a/libcxx/test/std/experimental/lit.local.cfg b/libcxx/test/std/experimental/lit.local.cfg
--- a/libcxx/test/std/experimental/lit.local.cfg
+++ b/libcxx/test/std/experimental/lit.local.cfg
@@ -1,3 +1,3 @@
 # Disable all of the experimental tests if the correct feature is not available.
-if 'c++experimental' not in config.available_features:
-  config.unsupported = True
+if "c++experimental" not in config.available_features:
+    config.unsupported = True
diff --git a/libcxx/test/std/input.output/file.streams/lit.local.cfg b/libcxx/test/std/input.output/file.streams/lit.local.cfg
--- a/libcxx/test/std/input.output/file.streams/lit.local.cfg
+++ b/libcxx/test/std/input.output/file.streams/lit.local.cfg
@@ -1,6 +1,6 @@
 # All non-trivial uses of iostreams require localization support
-if 'no-localization' in config.available_features:
-  config.unsupported = True
+if "no-localization" in config.available_features:
+    config.unsupported = True
 
-if 'no-fstream' in config.available_features:
-  config.unsupported = True
+if "no-fstream" in config.available_features:
+    config.unsupported = True
diff --git a/libcxx/test/std/input.output/filesystems/lit.local.cfg b/libcxx/test/std/input.output/filesystems/lit.local.cfg
--- a/libcxx/test/std/input.output/filesystems/lit.local.cfg
+++ b/libcxx/test/std/input.output/filesystems/lit.local.cfg
@@ -1,5 +1,5 @@
-if 'availability-filesystem-missing' in config.available_features:
-  config.unsupported = True
+if "availability-filesystem-missing" in config.available_features:
+    config.unsupported = True
 
-if 'no-filesystem' in config.available_features:
+if "no-filesystem" in config.available_features:
     config.unsupported = True
diff --git a/libcxx/test/std/input.output/input.output.general/lit.local.cfg b/libcxx/test/std/input.output/input.output.general/lit.local.cfg
--- a/libcxx/test/std/input.output/input.output.general/lit.local.cfg
+++ b/libcxx/test/std/input.output/input.output.general/lit.local.cfg
@@ -1,3 +1,3 @@
 # All non-trivial uses of iostreams require localization support
-if 'no-localization' in config.available_features:
-  config.unsupported = True
+if "no-localization" in config.available_features:
+    config.unsupported = True
diff --git a/libcxx/test/std/input.output/iostream.format/lit.local.cfg b/libcxx/test/std/input.output/iostream.format/lit.local.cfg
--- a/libcxx/test/std/input.output/iostream.format/lit.local.cfg
+++ b/libcxx/test/std/input.output/iostream.format/lit.local.cfg
@@ -1,3 +1,3 @@
 # All non-trivial uses of iostreams require localization support
-if 'no-localization' in config.available_features:
-  config.unsupported = True
+if "no-localization" in config.available_features:
+    config.unsupported = True
diff --git a/libcxx/test/std/input.output/iostream.forward/lit.local.cfg b/libcxx/test/std/input.output/iostream.forward/lit.local.cfg
--- a/libcxx/test/std/input.output/iostream.forward/lit.local.cfg
+++ b/libcxx/test/std/input.output/iostream.forward/lit.local.cfg
@@ -1,3 +1,3 @@
 # All non-trivial uses of iostreams require localization support
-if 'no-localization' in config.available_features:
-  config.unsupported = True
+if "no-localization" in config.available_features:
+    config.unsupported = True
diff --git a/libcxx/test/std/input.output/iostream.objects/lit.local.cfg b/libcxx/test/std/input.output/iostream.objects/lit.local.cfg
--- a/libcxx/test/std/input.output/iostream.objects/lit.local.cfg
+++ b/libcxx/test/std/input.output/iostream.objects/lit.local.cfg
@@ -1,3 +1,3 @@
 # All non-trivial uses of iostreams require localization support
-if 'no-localization' in config.available_features:
-  config.unsupported = True
+if "no-localization" in config.available_features:
+    config.unsupported = True
diff --git a/libcxx/test/std/input.output/iostreams.base/lit.local.cfg b/libcxx/test/std/input.output/iostreams.base/lit.local.cfg
--- a/libcxx/test/std/input.output/iostreams.base/lit.local.cfg
+++ b/libcxx/test/std/input.output/iostreams.base/lit.local.cfg
@@ -1,3 +1,3 @@
 # All non-trivial uses of iostreams require localization support
-if 'no-localization' in config.available_features:
-  config.unsupported = True
+if "no-localization" in config.available_features:
+    config.unsupported = True
diff --git a/libcxx/test/std/input.output/iostreams.requirements/lit.local.cfg b/libcxx/test/std/input.output/iostreams.requirements/lit.local.cfg
--- a/libcxx/test/std/input.output/iostreams.requirements/lit.local.cfg
+++ b/libcxx/test/std/input.output/iostreams.requirements/lit.local.cfg
@@ -1,3 +1,3 @@
 # All non-trivial uses of iostreams require localization support
-if 'no-localization' in config.available_features:
-  config.unsupported = True
+if "no-localization" in config.available_features:
+    config.unsupported = True
diff --git a/libcxx/test/std/input.output/stream.buffers/lit.local.cfg b/libcxx/test/std/input.output/stream.buffers/lit.local.cfg
--- a/libcxx/test/std/input.output/stream.buffers/lit.local.cfg
+++ b/libcxx/test/std/input.output/stream.buffers/lit.local.cfg
@@ -1,3 +1,3 @@
 # All non-trivial uses of iostreams require localization support
-if 'no-localization' in config.available_features:
-  config.unsupported = True
+if "no-localization" in config.available_features:
+    config.unsupported = True
diff --git a/libcxx/test/std/input.output/string.streams/lit.local.cfg b/libcxx/test/std/input.output/string.streams/lit.local.cfg
--- a/libcxx/test/std/input.output/string.streams/lit.local.cfg
+++ b/libcxx/test/std/input.output/string.streams/lit.local.cfg
@@ -1,3 +1,3 @@
 # All non-trivial uses of iostreams require localization support
-if 'no-localization' in config.available_features:
-  config.unsupported = True
+if "no-localization" in config.available_features:
+    config.unsupported = True
diff --git a/libcxx/test/std/iterators/stream.iterators/lit.local.cfg b/libcxx/test/std/iterators/stream.iterators/lit.local.cfg
--- a/libcxx/test/std/iterators/stream.iterators/lit.local.cfg
+++ b/libcxx/test/std/iterators/stream.iterators/lit.local.cfg
@@ -1,3 +1,3 @@
 # stream iterators rely on the streams library, which requires localization
-if 'no-localization' in config.available_features:
-  config.unsupported = True
+if "no-localization" in config.available_features:
+    config.unsupported = True
diff --git a/libcxx/test/std/localization/lit.local.cfg b/libcxx/test/std/localization/lit.local.cfg
--- a/libcxx/test/std/localization/lit.local.cfg
+++ b/libcxx/test/std/localization/lit.local.cfg
@@ -1,3 +1,3 @@
 # <locale> tests are obviously not supported when localization support is disabled
-if 'no-localization' in config.available_features:
-  config.unsupported = True
+if "no-localization" in config.available_features:
+    config.unsupported = True
diff --git a/libcxx/test/std/re/lit.local.cfg b/libcxx/test/std/re/lit.local.cfg
--- a/libcxx/test/std/re/lit.local.cfg
+++ b/libcxx/test/std/re/lit.local.cfg
@@ -1,3 +1,3 @@
 # Unfortunately, <regex> uses locales in regex_traits
-if 'no-localization' in config.available_features:
-  config.unsupported = True
+if "no-localization" in config.available_features:
+    config.unsupported = True
diff --git a/libcxx/test/std/strings/basic.string/string.nonmembers/string.io/lit.local.cfg b/libcxx/test/std/strings/basic.string/string.nonmembers/string.io/lit.local.cfg
--- a/libcxx/test/std/strings/basic.string/string.nonmembers/string.io/lit.local.cfg
+++ b/libcxx/test/std/strings/basic.string/string.nonmembers/string.io/lit.local.cfg
@@ -1,3 +1,3 @@
 # These std::string functions require iostreams, which requires localization
-if 'no-localization' in config.available_features:
-  config.unsupported = True
+if "no-localization" in config.available_features:
+    config.unsupported = True
diff --git a/libcxxabi/test/native/arm-linux-eabi/lit.local.cfg b/libcxxabi/test/native/arm-linux-eabi/lit.local.cfg
--- a/libcxxabi/test/native/arm-linux-eabi/lit.local.cfg
+++ b/libcxxabi/test/native/arm-linux-eabi/lit.local.cfg
@@ -1,6 +1,9 @@
 def is_arm_linux_eabi(triple):
-    return ('arm' in triple) and ('linux' in triple) and ('eabi' in triple)
+    return ("arm" in triple) and ("linux" in triple) and ("eabi" in triple)
 
-is_native = hasattr(config.root, 'target_triple') and (config.root.host_triple == config.root.target_triple)
+
+is_native = hasattr(config.root, "target_triple") and (
+    config.root.host_triple == config.root.target_triple
+)
 if not is_native or not is_arm_linux_eabi(config.root.host_triple):
     config.unsupported = True