Use pathlib.Path in main cibuildwheel files

cibuildwheel/__main__.py

@@ -4,6 +4,7 @@ import sys
 import textwrap
 import traceback
 from configparser import ConfigParser
+from pathlib import Path
 
 from typing import Any, Dict, List, Optional, overload
 
@@ -114,8 +115,8 @@ def main() -> None:
                   file=sys.stderr)
             exit(2)
 
-    package_dir = args.package_dir
+    package_dir = Path(args.package_dir)
-    output_dir = args.output_dir
+    output_dir = Path(args.output_dir)
 
     if platform == 'linux':
         repair_command_default = 'auditwheel repair -w {dest_dir} {wheel}'
@@ -149,7 +150,8 @@ def main() -> None:
     elif dependency_versions == 'latest':
         dependency_constraints = None
     else:
-        dependency_constraints = DependencyConstraints(dependency_versions)
+        dependency_versions_path = Path(dependency_versions)
+        dependency_constraints = DependencyConstraints(dependency_versions_path)
 
     if test_extras:
         test_extras = f'[{test_extras}]'
@@ -163,7 +165,7 @@ def main() -> None:
     # This needs to be passed on to the docker container in linux.py
     os.environ['CIBUILDWHEEL'] = '1'
 
-    if not any(os.path.exists(os.path.join(package_dir, name))
+    if not any((package_dir / name).exists()
                for name in ["setup.py", "setup.cfg", "pyproject.toml"]):
         print('cibuildwheel: Could not find setup.py, setup.cfg or pyproject.toml at root of package', file=sys.stderr)
         exit(2)
@@ -174,9 +176,7 @@ def main() -> None:
 
     manylinux_images: Optional[Dict[str, str]] = None
     if platform == 'linux':
-        pinned_docker_images_file = os.path.join(
+        pinned_docker_images_file = Path(__file__).parent / 'resources' / 'pinned_docker_images.cfg'
-            os.path.dirname(__file__), 'resources', 'pinned_docker_images.cfg'
-        )
         all_pinned_docker_images = ConfigParser()
         all_pinned_docker_images.read(pinned_docker_images_file)
         # all_pinned_docker_images looks like a dict of dicts, e.g.
@@ -224,8 +224,8 @@ def main() -> None:
 
     print_preamble(platform, build_options)
 
-    if not os.path.exists(output_dir):
+    if not output_dir.exists():
-        os.makedirs(output_dir)
+        output_dir.mkdir(parents=True)
 
     if platform == 'linux':
         cibuildwheel.linux.build(build_options)

cibuildwheel/linux.py

@@ -5,6 +5,7 @@ import subprocess
 import sys
 import textwrap
 import uuid
+from pathlib import Path
 
 from typing import List, NamedTuple, Optional, Union
 
@@ -104,10 +105,12 @@ def build(options: BuildOptions) -> None:
         ('pp', 'manylinux_x86_64', options.manylinux_images['pypy_x86_64']),
     ]
 
-    if not os.path.realpath(options.package_dir).startswith(os.path.realpath('.')):
+    pwd = Path().resolve()
+    abs_package_dir = options.package_dir.resolve()
+    if pwd != abs_package_dir and pwd not in abs_package_dir.parents:
         raise Exception('package_dir must be inside the working directory')
 
-    container_package_dir = os.path.join('/project', os.path.relpath(options.package_dir, '.'))
+    container_package_dir = Path('/project') / abs_package_dir.relative_to(pwd)
 
     for implementation, platform_tag, docker_image in platforms:
         platform_configs = [c for c in python_configurations if c.identifier.startswith(implementation) and c.identifier.endswith(platform_tag)]
@@ -272,7 +275,7 @@ def build(options: BuildOptions) -> None:
             # copy the output back into the host
             call(['docker', 'cp',
                   container_name + ':/output/.',
-                  os.path.abspath(options.output_dir)])
+                  str(options.output_dir.resolve())])
         except subprocess.CalledProcessError as error:
             troubleshoot(options.package_dir, error)
             exit(1)
@@ -281,16 +284,11 @@ def build(options: BuildOptions) -> None:
             call(['docker', 'rm', '--force', '-v', container_name])
 
 
-def troubleshoot(package_dir: str, error: Exception) -> None:
+def troubleshoot(package_dir: Path, error: Exception) -> None:
     if (isinstance(error, subprocess.CalledProcessError) and 'exec' in error.cmd):
         # the bash script failed
         print('Checking for common errors...')
-        so_files = []
+        so_files = list(package_dir.glob('**/*.so'))
-        for root, dirs, files in os.walk(package_dir):
-            for name in files:
-                _, ext = os.path.splitext(name)
-                if ext == '.so':
-                    so_files.append(os.path.join(root, name))
 
         if so_files:
             print(textwrap.dedent('''
@@ -304,5 +302,5 @@ def troubleshoot(package_dir: str, error: Exception) -> None:
             '''))
 
             print('  Files detected:')
-            print('\n'.join(['    ' + f for f in so_files]))
+            print('\n'.join(['    ' + str(f) for f in so_files]))
             print('')

cibuildwheel/macos.py

@@ -5,6 +5,7 @@ import subprocess
 import sys
 import tempfile
 from glob import glob
+from pathlib import Path
 
 from typing import Dict, List, Optional, NamedTuple, Union
 
@@ -24,7 +25,7 @@ def call(args: Union[str, List[str]], env: Optional[Dict[str, str]] = None, cwd:
     if shell:
         print(f'+ {args}')
     else:
-        print('+ ' + ' '.join(shlex.quote(a) for a in args))
+        print('+ ' + ' '.join(shlex.quote(str(a)) for a in args))
 
     return subprocess.check_call(args, env=env, cwd=cwd, shell=shell)
 
@@ -52,41 +53,41 @@ def get_python_configurations(build_selector: BuildSelector) -> List[PythonConfi
     return [c for c in python_configurations if build_selector(c.identifier)]
 
 
-SYMLINKS_DIR = '/tmp/cibw_bin'
+SYMLINKS_DIR = Path('/tmp/cibw_bin')
 
 
-def make_symlinks(installation_bin_path: str, python_executable: str, pip_executable: str) -> None:
+def make_symlinks(installation_bin_path: Path, python_executable: str, pip_executable: str) -> None:
-    assert os.path.exists(os.path.join(installation_bin_path, python_executable))
+    assert (installation_bin_path / python_executable).exists()
 
     # Python bin folders on Mac don't symlink `python3` to `python`, and neither
     # does PyPy for `pypy` or `pypy3`, so we do that so `python` and `pip` always
     # point to the active configuration.
-    if os.path.exists(SYMLINKS_DIR):
+    if SYMLINKS_DIR.exists():
         shutil.rmtree(SYMLINKS_DIR)
-    os.makedirs(SYMLINKS_DIR)
+    SYMLINKS_DIR.mkdir(parents=True)
 
-    os.symlink(os.path.join(installation_bin_path, python_executable), os.path.join(SYMLINKS_DIR, 'python'))
+    (SYMLINKS_DIR / 'python').symlink_to(installation_bin_path / python_executable)
-    os.symlink(os.path.join(installation_bin_path, python_executable + '-config'), os.path.join(SYMLINKS_DIR, 'python-config'))
+    (SYMLINKS_DIR / 'python-config').symlink_to(installation_bin_path / (python_executable + '-config'))
-    os.symlink(os.path.join(installation_bin_path, pip_executable), os.path.join(SYMLINKS_DIR, 'pip'))
+    (SYMLINKS_DIR / 'pip').symlink_to(installation_bin_path / pip_executable)
 
 
-def install_cpython(version: str, url: str) -> str:
+def install_cpython(version: str, url: str) -> Path:
     installed_system_packages = subprocess.check_output(['pkgutil', '--pkgs'], universal_newlines=True).splitlines()
 
     # if this version of python isn't installed, get it from python.org and install
     python_package_identifier = f'org.python.Python.PythonFramework-{version}'
     if python_package_identifier not in installed_system_packages:
         # download the pkg
-        download(url, '/tmp/Python.pkg')
+        download(url, Path('/tmp/Python.pkg'))
         # install
         call(['sudo', 'installer', '-pkg', '/tmp/Python.pkg', '-target', '/'])
         # patch open ssl
         if version == '3.5':
             open_ssl_patch_url = f'https://github.com/mayeut/patch-macos-python-openssl/releases/download/v1.0.2u/patch-macos-python-{version}-openssl-v1.0.2u.tar.gz'
-            download(open_ssl_patch_url, '/tmp/python-patch.tar.gz')
+            download(open_ssl_patch_url, Path('/tmp/python-patch.tar.gz'))
             call(['sudo', 'tar', '-C', f'/Library/Frameworks/Python.framework/Versions/{version}/', '-xmf', '/tmp/python-patch.tar.gz'])
 
-    installation_bin_path = f'/Library/Frameworks/Python.framework/Versions/{version}/bin'
+    installation_bin_path = Path(f'/Library/Frameworks/Python.framework/Versions/{version}/bin')
     python_executable = 'python3' if version[0] == '3' else 'python'
     pip_executable = 'pip3' if version[0] == '3' else 'pip'
     make_symlinks(installation_bin_path, python_executable, pip_executable)
@@ -94,16 +95,18 @@ def install_cpython(version: str, url: str) -> str:
     return installation_bin_path
 
 
-def install_pypy(version: str, url: str) -> str:
+def install_pypy(version: str, url: str) -> Path:
     pypy_tar_bz2 = url.rsplit('/', 1)[-1]
-    assert pypy_tar_bz2.endswith(".tar.bz2")
+    extension = ".tar.bz2"
-    pypy_base_filename = os.path.splitext(os.path.splitext(pypy_tar_bz2)[0])[0]
+    assert pypy_tar_bz2.endswith(extension)
-    installation_path = os.path.join('/tmp', pypy_base_filename)
+    pypy_base_filename = pypy_tar_bz2[:-len(extension)]
-    if not os.path.exists(installation_path):
+    installation_path = Path('/tmp') / pypy_base_filename
-        download(url, os.path.join("/tmp", pypy_tar_bz2))
+    if not installation_path.exists():
-        call(['tar', '-C', '/tmp', '-xf', os.path.join("/tmp", pypy_tar_bz2)])
+        downloaded_tar_bz2 = Path("/tmp") / pypy_tar_bz2
+        download(url, downloaded_tar_bz2)
+        call(['tar', '-C', '/tmp', '-xf', str(downloaded_tar_bz2)])
 
-    installation_bin_path = os.path.join(installation_path, 'bin')
+    installation_bin_path = installation_path / 'bin'
     python_executable = 'pypy3' if version[0] == '3' else 'pypy'
     pip_executable = 'pip3' if version[0] == '3' else 'pip'
     make_symlinks(installation_bin_path, python_executable, pip_executable)
@@ -121,8 +124,8 @@ def setup_python(python_configuration: PythonConfiguration, dependency_constrain
 
     env = os.environ.copy()
     env['PATH'] = os.pathsep.join([
-        SYMLINKS_DIR,
+        str(SYMLINKS_DIR),
-        installation_bin_path,
+        str(installation_bin_path),
         env['PATH'],
     ])
 
@@ -144,8 +147,8 @@ def setup_python(python_configuration: PythonConfiguration, dependency_constrain
         exit(1)
 
     # install pip & wheel
-    call(['python', get_pip_script] + dependency_constraint_flags, env=env, cwd="/tmp")
+    call(['python', str(get_pip_script)] + dependency_constraint_flags, env=env, cwd="/tmp")
-    assert os.path.exists(os.path.join(installation_bin_path, 'pip'))
+    assert (installation_bin_path / 'pip').exists()
     call(['which', 'pip'], env=env)
     call(['pip', '--version'], env=env)
     which_pip = subprocess.check_output(['which', 'pip'], env=env, universal_newlines=True).strip()
@@ -170,9 +173,9 @@ def setup_python(python_configuration: PythonConfiguration, dependency_constrain
 
 
 def build(options: BuildOptions) -> None:
-    temp_dir = tempfile.mkdtemp(prefix='cibuildwheel')
+    temp_dir = Path(tempfile.mkdtemp(prefix='cibuildwheel'))
-    built_wheel_dir = os.path.join(temp_dir, 'built_wheel')
+    built_wheel_dir = temp_dir / 'built_wheel'
-    repaired_wheel_dir = os.path.join(temp_dir, 'repaired_wheel')
+    repaired_wheel_dir = temp_dir / 'repaired_wheel'
 
     python_configurations = get_python_configurations(options.build_selector)
 
@@ -180,7 +183,7 @@ def build(options: BuildOptions) -> None:
         dependency_constraint_flags = []
         if options.dependency_constraints:
             dependency_constraint_flags = [
-                '-c', options.dependency_constraints.get_for_python_version(config.version)
+                '-c', str(options.dependency_constraints.get_for_python_version(config.version))
             ]
 
         env = setup_python(config, dependency_constraint_flags, options.environment)
@@ -191,39 +194,39 @@ def build(options: BuildOptions) -> None:
             call(before_build_prepared, env=env, shell=True)
 
         # build the wheel
-        if os.path.exists(built_wheel_dir):
+        if built_wheel_dir.exists():
             shutil.rmtree(built_wheel_dir)
-        os.makedirs(built_wheel_dir)
+        built_wheel_dir.mkdir(parents=True)
-        # os.path.abspath is need. Without it pip wheel may try to fetch package from pypi.org
+        # Path.resolve() is needed. Without it pip wheel may try to fetch package from pypi.org
         # see https://github.com/joerick/cibuildwheel/pull/369
-        call(['pip', 'wheel', os.path.abspath(options.package_dir), '-w', built_wheel_dir, '--no-deps'] + get_build_verbosity_extra_flags(options.build_verbosity), env=env)
+        call(['pip', 'wheel', str(options.package_dir.resolve()), '-w', str(built_wheel_dir), '--no-deps'] + get_build_verbosity_extra_flags(options.build_verbosity), env=env)
-        built_wheel = glob(os.path.join(built_wheel_dir, '*.whl'))[0]
+        built_wheel = next(built_wheel_dir.glob('*.whl'))
 
         # repair the wheel
-        if os.path.exists(repaired_wheel_dir):
+        if repaired_wheel_dir.exists():
             shutil.rmtree(repaired_wheel_dir)
-        os.makedirs(repaired_wheel_dir)
+        repaired_wheel_dir.mkdir(parents=True)
-        if built_wheel.endswith('none-any.whl') or not options.repair_command:
+        if built_wheel.name.endswith('none-any.whl') or not options.repair_command:
             # pure Python wheel or empty repair command
-            shutil.move(built_wheel, repaired_wheel_dir)
+            shutil.move(str(built_wheel), repaired_wheel_dir)
         else:
             repair_command_prepared = prepare_command(options.repair_command, wheel=built_wheel, dest_dir=repaired_wheel_dir)
             call(repair_command_prepared, env=env, shell=True)
-        repaired_wheel = glob(os.path.join(repaired_wheel_dir, '*.whl'))[0]
+        repaired_wheel = next(repaired_wheel_dir.glob('*.whl'))
 
         if options.test_command:
             # set up a virtual environment to install and test from, to make sure
             # there are no dependencies that were pulled in at build time.
             call(['pip', 'install', 'virtualenv'] + dependency_constraint_flags, env=env)
-            venv_dir = tempfile.mkdtemp()
+            venv_dir = Path(tempfile.mkdtemp())
 
             # Use --no-download to ensure determinism by using seed libraries
             # built into virtualenv
-            call(['python', '-m', 'virtualenv', '--no-download', venv_dir], env=env)
+            call(['python', '-m', 'virtualenv', '--no-download', str(venv_dir)], env=env)
 
             virtualenv_env = env.copy()
             virtualenv_env['PATH'] = os.pathsep.join([
-                os.path.join(venv_dir, 'bin'),
+                str(venv_dir / 'bin'),
                 virtualenv_env['PATH'],
             ])
 
@@ -235,7 +238,7 @@ def build(options: BuildOptions) -> None:
                 call(before_test_prepared, env=virtualenv_env, shell=True)
 
             # install the wheel
-            call(['pip', 'install', repaired_wheel + options.test_extras], env=virtualenv_env)
+            call(['pip', 'install', str(repaired_wheel) + options.test_extras], env=virtualenv_env)
 
             # test the wheel
             if options.test_requires:
@@ -246,8 +249,8 @@ def build(options: BuildOptions) -> None:
             # and not the repo code)
             test_command_prepared = prepare_command(
                 options.test_command,
-                project=os.path.abspath('.'),
+                project=Path('.').resolve(),
-                package=os.path.abspath(options.package_dir)
+                package=options.package_dir
             )
             call(test_command_prepared, cwd=os.environ['HOME'], env=virtualenv_env, shell=True)
 
@@ -255,5 +258,5 @@ def build(options: BuildOptions) -> None:
             shutil.rmtree(venv_dir)
 
         # we're all done here; move it to output (overwrite existing)
-        dst = os.path.join(options.output_dir, os.path.basename(repaired_wheel))
+        dst = options.output_dir / repaired_wheel.name
-        shutil.move(repaired_wheel, dst)
+        shutil.move(str(repaired_wheel), dst)

cibuildwheel/util.py

@@ -1,14 +1,15 @@
 import os
 import urllib.request
 from fnmatch import fnmatch
+from pathlib import Path
 from time import sleep
 
-from typing import Dict, List, NamedTuple, Optional
+from typing import Dict, List, NamedTuple, Optional, Union
 
 from .environment import ParsedEnvironment
 
 
-def prepare_command(command: str, **kwargs: str) -> str:
+def prepare_command(command: str, **kwargs: Union[str, os.PathLike]) -> str:
     '''
     Preprocesses a command by expanding variables like {python}.
 
@@ -58,11 +59,11 @@ class Unbuffered:
         return getattr(self.stream, attr)
 
 
-def download(url: str, dest: str) -> None:
+def download(url: str, dest: Path) -> None:
-    print('+ Download ' + url + ' to ' + dest)
+    print(f'+ Download {url} to {dest}')
-    dest_dir = os.path.dirname(dest)
+    dest_dir = dest.parent
-    if not os.path.exists(dest_dir):
+    if not dest_dir.exists():
-        os.makedirs(dest_dir)
+        dest_dir.mkdir(parents=True)
 
     repeat_num = 3
     for i in range(repeat_num):
@@ -76,40 +77,39 @@ def download(url: str, dest: str) -> None:
         break
 
     try:
-        with open(dest, 'wb') as file:
+        dest.write_bytes(response.read())
-            file.write(response.read())
     finally:
         response.close()
 
 
 class DependencyConstraints:
-    def __init__(self, base_file_path: str):
+    def __init__(self, base_file_path: Path):
-        assert os.path.exists(base_file_path)
+        assert base_file_path.exists()
-        self.base_file_path = os.path.abspath(base_file_path)
+        self.base_file_path = base_file_path.resolve()
 
     @staticmethod
     def with_defaults() -> 'DependencyConstraints':
         return DependencyConstraints(
-            base_file_path=os.path.join(os.path.dirname(__file__), 'resources', 'constraints.txt')
+            base_file_path=Path(__file__).parent / 'resources' / 'constraints.txt'
         )
 
-    def get_for_python_version(self, version: str) -> str:
+    def get_for_python_version(self, version: str) -> Path:
         version_parts = version.split('.')
 
         # try to find a version-specific dependency file e.g. if
         # ./constraints.txt is the base, look for ./constraints-python27.txt
-        base, ext = os.path.splitext(self.base_file_path)
+        specific_stem = self.base_file_path.stem + f'-python{version_parts[0]}{version_parts[1]}'
-        specific = base + f'-python{version_parts[0]}{version_parts[1]}'
+        sepcific_name = specific_stem + self.base_file_path.suffix
-        specific_file_path = specific + ext
+        specific_file_path = self.base_file_path.with_name(sepcific_name)
-        if os.path.exists(specific_file_path):
+        if specific_file_path.exists():
             return specific_file_path
         else:
             return self.base_file_path
 
 
 class BuildOptions(NamedTuple):
-    package_dir: str
+    package_dir: Path
-    output_dir: str
+    output_dir: Path
     build_selector: BuildSelector
     environment: ParsedEnvironment
     before_build: Optional[str]
@@ -123,5 +123,5 @@ class BuildOptions(NamedTuple):
     build_verbosity: int
 
 
-resources_dir = os.path.abspath(os.path.join(os.path.dirname(__file__), 'resources'))
+resources_dir = Path(__file__).resolve().parent / 'resources'
-get_pip_script = os.path.join(resources_dir, 'get-pip.py')
+get_pip_script = resources_dir / 'get-pip.py'

cibuildwheel/windows.py

@@ -4,6 +4,7 @@ import subprocess
 import sys
 import tempfile
 from glob import glob
+from pathlib import Path
 from zipfile import ZipFile
 
 from typing import Dict, List, Optional, NamedTuple
@@ -19,7 +20,7 @@ from .util import (
 )
 
 
-IS_RUNNING_ON_AZURE = os.path.exists('C:\\hostedtoolcache')
+IS_RUNNING_ON_AZURE = Path('C:\\hostedtoolcache').exists()
 IS_RUNNING_ON_TRAVIS = os.environ.get('TRAVIS_OS_NAME') == 'windows'
 
 
@@ -71,36 +72,38 @@ def get_python_configurations(build_selector: BuildSelector) -> List[PythonConfi
     return python_configurations
 
 
-def extract_zip(zip_src: str, dest: str) -> None:
+def extract_zip(zip_src: Path, dest: Path) -> None:
     with ZipFile(zip_src) as zip:
         zip.extractall(dest)
 
 
-def install_cpython(version: str, arch: str, nuget: str) -> str:
+def install_cpython(version: str, arch: str, nuget: Path) -> Path:
     nuget_args = get_nuget_args(version, arch)
-    installation_path = os.path.join(nuget_args[-1], nuget_args[0] + '.' + version, 'tools')
+    installation_path = Path(nuget_args[-1]) / (nuget_args[0] + '.' + version) / 'tools'
-    shell([nuget, 'install'] + nuget_args)
+    shell([str(nuget), 'install'] + nuget_args)
     return installation_path
 
 
-def install_pypy(version: str, arch: str, url: str) -> str:
+def install_pypy(version: str, arch: str, url: str) -> Path:
     assert arch == '32'
     # Inside the PyPy zip file is a directory with the same name
     zip_filename = url.rsplit('/', 1)[-1]
-    installation_path = os.path.join('C:\\cibw', os.path.splitext(zip_filename)[0])
+    extension = ".zip"
-    if not os.path.exists(installation_path):
+    assert zip_filename.endswith(extension)
-        pypy_zip = os.path.join('C:\\cibw', zip_filename)
+    installation_path = Path('C:\\cibw') / zip_filename[:-len(extension)]
+    if not installation_path.exists():
+        pypy_zip = Path('C:\\cibw') / zip_filename
         download(url, pypy_zip)
         # Extract to the parent directory because the zip file still contains a directory
-        extract_zip(pypy_zip, os.path.dirname(installation_path))
+        extract_zip(pypy_zip, installation_path.parent)
         pypy_exe = 'pypy3.exe' if version[0] == '3' else 'pypy.exe'
-        shell(['mklink', os.path.join(installation_path, 'python.exe'), os.path.join(installation_path, pypy_exe)])
+        (installation_path / pypy_exe).symlink_to(installation_path / 'python.exe')
     return installation_path
 
 
 def setup_python(python_configuration: PythonConfiguration, dependency_constraint_flags: List[str], environment: ParsedEnvironment) -> Dict[str, str]:
-    nuget = 'C:\\cibw\\nuget.exe'
+    nuget = Path('C:\\cibw\\nuget.exe')
-    if not os.path.exists(nuget):
+    if not nuget.exists():
         download('https://dist.nuget.org/win-x86-commandline/latest/nuget.exe', nuget)
 
     if python_configuration.identifier.startswith('cp'):
@@ -111,15 +114,15 @@ def setup_python(python_configuration: PythonConfiguration, dependency_constrain
     else:
         raise ValueError("Unknown Python implementation")
 
-    assert os.path.exists(os.path.join(installation_path, 'python.exe'))
+    assert (installation_path / 'python.exe').exists()
 
     # set up PATH and environment variables for run_with_env
     env = os.environ.copy()
     env['PYTHON_VERSION'] = python_configuration.version
     env['PYTHON_ARCH'] = python_configuration.arch
     env['PATH'] = os.pathsep.join([
-        installation_path,
+        str(installation_path),
-        os.path.join(installation_path, 'Scripts'),
+        str(installation_path / 'Scripts'),
         env['PATH']
     ])
     # update env with results from CIBW_ENVIRONMENT
@@ -130,16 +133,16 @@ def setup_python(python_configuration: PythonConfiguration, dependency_constrain
     shell(['python', '--version'], env=env)
     shell(['python', '-c', '"import struct; print(struct.calcsize(\'P\') * 8)"'], env=env)
     where_python = subprocess.check_output(['where', 'python'], env=env, universal_newlines=True).splitlines()[0].strip()
-    if where_python != os.path.join(installation_path, 'python.exe'):
+    if where_python != str(installation_path / 'python.exe'):
         print("cibuildwheel: python available on PATH doesn't match our installed instance. If you have modified PATH, ensure that you don't overwrite cibuildwheel's entry or insert python above it.", file=sys.stderr)
         exit(1)
 
     # make sure pip is installed
-    if not os.path.exists(os.path.join(installation_path, 'Scripts', 'pip.exe')):
+    if not (installation_path / 'Scripts' / 'pip.exe').exists():
-        shell(['python', get_pip_script] + dependency_constraint_flags, env=env, cwd="C:\\cibw")
+        shell(['python', str(get_pip_script)] + dependency_constraint_flags, env=env, cwd="C:\\cibw")
-    assert os.path.exists(os.path.join(installation_path, 'Scripts', 'pip.exe'))
+    assert (installation_path / 'Scripts' / 'pip.exe').exists()
     where_pip = subprocess.check_output(['where', 'pip'], env=env, universal_newlines=True).splitlines()[0].strip()
-    if where_pip.strip() != os.path.join(installation_path, 'Scripts', 'pip.exe'):
+    if where_pip.strip() != str(installation_path / 'Scripts' / 'pip.exe'):
         print("cibuildwheel: pip available on PATH doesn't match our installed instance. If you have modified PATH, ensure that you don't overwrite cibuildwheel's entry or insert pip above it.", file=sys.stderr)
         exit(1)
 
@@ -152,12 +155,12 @@ def setup_python(python_configuration: PythonConfiguration, dependency_constrain
 
 
 def build(options: BuildOptions) -> None:
-    temp_dir = tempfile.mkdtemp(prefix='cibuildwheel')
+    temp_dir = Path(tempfile.mkdtemp(prefix='cibuildwheel'))
-    built_wheel_dir = os.path.join(temp_dir, 'built_wheel')
+    built_wheel_dir = temp_dir / 'built_wheel'
-    repaired_wheel_dir = os.path.join(temp_dir, 'repaired_wheel')
+    repaired_wheel_dir = temp_dir / 'repaired_wheel'
 
     # install nuget as best way to provide python
-    nuget = 'C:\\cibw\\nuget.exe'
+    nuget = Path('C:\\cibw\\nuget.exe')
     download('https://dist.nuget.org/win-x86-commandline/latest/nuget.exe', nuget)
 
     python_configurations = get_python_configurations(options.build_selector)
@@ -165,7 +168,7 @@ def build(options: BuildOptions) -> None:
         dependency_constraint_flags = []
         if options.dependency_constraints:
             dependency_constraint_flags = [
-                '-c', options.dependency_constraints.get_for_python_version(config.version)
+                '-c', str(options.dependency_constraints.get_for_python_version(config.version))
             ]
 
         # install Python
@@ -177,39 +180,39 @@ def build(options: BuildOptions) -> None:
             shell([before_build_prepared], env=env)
 
         # build the wheel
-        if os.path.exists(built_wheel_dir):
+        if built_wheel_dir.exists():
             shutil.rmtree(built_wheel_dir)
-        os.makedirs(built_wheel_dir)
+        built_wheel_dir.mkdir(parents=True)
-        # os.path.abspath is need. Without it pip wheel may try to fetch package from pypi.org
+        # Path.resolve() is needed. Without it pip wheel may try to fetch package from pypi.org
         # see https://github.com/joerick/cibuildwheel/pull/369
-        shell(['pip', 'wheel', os.path.abspath(options.package_dir), '-w', built_wheel_dir, '--no-deps'] + get_build_verbosity_extra_flags(options.build_verbosity), env=env)
+        shell(['pip', 'wheel', str(options.package_dir.resolve()), '-w', str(built_wheel_dir), '--no-deps'] + get_build_verbosity_extra_flags(options.build_verbosity), env=env)
-        built_wheel = glob(os.path.join(built_wheel_dir, '*.whl'))[0]
+        built_wheel = next(built_wheel_dir.glob('*.whl'))
 
         # repair the wheel
-        if os.path.exists(repaired_wheel_dir):
+        if repaired_wheel_dir.exists():
             shutil.rmtree(repaired_wheel_dir)
-        os.makedirs(repaired_wheel_dir)
+        repaired_wheel_dir.mkdir(parents=True)
-        if built_wheel.endswith('none-any.whl') or not options.repair_command:
+        if built_wheel.name.endswith('none-any.whl') or not options.repair_command:
             # pure Python wheel or empty repair command
-            shutil.move(built_wheel, repaired_wheel_dir)
+            shutil.move(str(built_wheel), repaired_wheel_dir)
         else:
             repair_command_prepared = prepare_command(options.repair_command, wheel=built_wheel, dest_dir=repaired_wheel_dir)
             shell([repair_command_prepared], env=env)
-        repaired_wheel = glob(os.path.join(repaired_wheel_dir, '*.whl'))[0]
+        repaired_wheel = next(repaired_wheel_dir.glob('*.whl'))
 
         if options.test_command:
             # set up a virtual environment to install and test from, to make sure
             # there are no dependencies that were pulled in at build time.
             shell(['pip', 'install', 'virtualenv'] + dependency_constraint_flags, env=env)
-            venv_dir = tempfile.mkdtemp()
+            venv_dir = Path(tempfile.mkdtemp())
 
             # Use --no-download to ensure determinism by using seed libraries
             # built into virtualenv
-            shell(['python', '-m', 'virtualenv', '--no-download', venv_dir], env=env)
+            shell(['python', '-m', 'virtualenv', '--no-download', str(venv_dir)], env=env)
 
             virtualenv_env = env.copy()
             virtualenv_env['PATH'] = os.pathsep.join([
-                os.path.join(venv_dir, 'Scripts'),
+                str(venv_dir / 'Scripts'),
                 virtualenv_env['PATH'],
             ])
 
@@ -225,7 +228,7 @@ def build(options: BuildOptions) -> None:
                 shell([before_test_prepared], env=virtualenv_env)
 
             # install the wheel
-            shell(['pip', 'install', repaired_wheel + options.test_extras], env=virtualenv_env)
+            shell(['pip', 'install', str(repaired_wheel) + options.test_extras], env=virtualenv_env)
 
             # test the wheel
             if options.test_requires:
@@ -236,8 +239,8 @@ def build(options: BuildOptions) -> None:
             # and not the repo code)
             test_command_prepared = prepare_command(
                 options.test_command,
-                project=os.path.abspath('.'),
+                project=Path('.').resolve(),
-                package=os.path.abspath(options.package_dir)
+                package=options.package_dir.resolve()
             )
             shell([test_command_prepared], cwd='c:\\', env=virtualenv_env)
 
@@ -245,7 +248,7 @@ def build(options: BuildOptions) -> None:
             shutil.rmtree(venv_dir)
 
         # we're all done here; move it to output (remove if already exists)
-        dst = os.path.join(options.output_dir, os.path.basename(repaired_wheel))
+        dst = options.output_dir / repaired_wheel.name
-        if os.path.isfile(dst):
+        if dst.is_file():
-            os.remove(dst)
+            dst.unlink()
-        shutil.move(repaired_wheel, dst)
+        shutil.move(str(repaired_wheel), dst)