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Diffstat (limited to 'pre_commit/languages/python.py')
| -rw-r--r-- | pre_commit/languages/python.py | 210 |
1 files changed, 210 insertions, 0 deletions
diff --git a/pre_commit/languages/python.py b/pre_commit/languages/python.py new file mode 100644 index 0000000..5073a8b --- /dev/null +++ b/pre_commit/languages/python.py @@ -0,0 +1,210 @@ +import contextlib +import functools +import os +import sys +from typing import Callable +from typing import ContextManager +from typing import Generator +from typing import Optional +from typing import Sequence +from typing import Tuple + +import pre_commit.constants as C +from pre_commit.envcontext import envcontext +from pre_commit.envcontext import PatchesT +from pre_commit.envcontext import UNSET +from pre_commit.envcontext import Var +from pre_commit.hook import Hook +from pre_commit.languages import helpers +from pre_commit.parse_shebang import find_executable +from pre_commit.prefix import Prefix +from pre_commit.util import CalledProcessError +from pre_commit.util import clean_path_on_failure +from pre_commit.util import cmd_output +from pre_commit.util import cmd_output_b + +ENVIRONMENT_DIR = 'py_env' + + +def bin_dir(venv: str) -> str: + """On windows there's a different directory for the virtualenv""" + bin_part = 'Scripts' if os.name == 'nt' else 'bin' + return os.path.join(venv, bin_part) + + +def get_env_patch(venv: str) -> PatchesT: + return ( + ('PYTHONHOME', UNSET), + ('VIRTUAL_ENV', venv), + ('PATH', (bin_dir(venv), os.pathsep, Var('PATH'))), + ) + + +def _find_by_py_launcher( + version: str, +) -> Optional[str]: # pragma: no cover (windows only) + if version.startswith('python'): + num = version[len('python'):] + try: + cmd = ('py', f'-{num}', '-c', 'import sys; print(sys.executable)') + return cmd_output(*cmd)[1].strip() + except CalledProcessError: + pass + return None + + +def _find_by_sys_executable() -> Optional[str]: + def _norm(path: str) -> Optional[str]: + _, exe = os.path.split(path.lower()) + exe, _, _ = exe.partition('.exe') + if exe not in {'python', 'pythonw'} and find_executable(exe): + return exe + return None + + # On linux, I see these common sys.executables: + # + # system `python`: /usr/bin/python -> python2.7 + # system `python2`: /usr/bin/python2 -> python2.7 + # virtualenv v: v/bin/python (will not return from this loop) + # virtualenv v -ppython2: v/bin/python -> python2 + # virtualenv v -ppython2.7: v/bin/python -> python2.7 + # virtualenv v -ppypy: v/bin/python -> v/bin/pypy + for path in (sys.executable, os.path.realpath(sys.executable)): + exe = _norm(path) + if exe: + return exe + return None + + +@functools.lru_cache(maxsize=1) +def get_default_version() -> str: # pragma: no cover (platform dependent) + # First attempt from `sys.executable` (or the realpath) + exe = _find_by_sys_executable() + if exe: + return exe + + # Next try the `pythonX.X` executable + exe = f'python{sys.version_info[0]}.{sys.version_info[1]}' + if find_executable(exe): + return exe + + if _find_by_py_launcher(exe): + return exe + + # Give a best-effort try for windows + default_folder_name = exe.replace('.', '') + if os.path.exists(fr'C:\{default_folder_name}\python.exe'): + return exe + + # We tried! + return C.DEFAULT + + +def _sys_executable_matches(version: str) -> bool: + if version == 'python': + return True + elif not version.startswith('python'): + return False + + try: + info = tuple(int(p) for p in version[len('python'):].split('.')) + except ValueError: + return False + + return sys.version_info[:len(info)] == info + + +def norm_version(version: str) -> str: + # first see if our current executable is appropriate + if _sys_executable_matches(version): + return sys.executable + + if os.name == 'nt': # pragma: no cover (windows) + version_exec = _find_by_py_launcher(version) + if version_exec: + return version_exec + + # Try looking up by name + version_exec = find_executable(version) + if version_exec and version_exec != version: + return version_exec + + # If it is in the form pythonx.x search in the default + # place on windows + if version.startswith('python'): + default_folder_name = version.replace('.', '') + return fr'C:\{default_folder_name}\python.exe' + + # Otherwise assume it is a path + return os.path.expanduser(version) + + +def py_interface( + _dir: str, + _make_venv: Callable[[str, str], None], +) -> Tuple[ + Callable[[Prefix, str], ContextManager[None]], + Callable[[Prefix, str], bool], + Callable[[Hook, Sequence[str], bool], Tuple[int, bytes]], + Callable[[Prefix, str, Sequence[str]], None], +]: + @contextlib.contextmanager + def in_env( + prefix: Prefix, + language_version: str, + ) -> Generator[None, None, None]: + envdir = prefix.path(helpers.environment_dir(_dir, language_version)) + with envcontext(get_env_patch(envdir)): + yield + + def healthy(prefix: Prefix, language_version: str) -> bool: + envdir = helpers.environment_dir(_dir, language_version) + exe_name = 'python.exe' if sys.platform == 'win32' else 'python' + py_exe = prefix.path(bin_dir(envdir), exe_name) + with in_env(prefix, language_version): + retcode, _, _ = cmd_output_b( + py_exe, '-c', 'import ctypes, datetime, io, os, ssl, weakref', + cwd='/', + retcode=None, + ) + return retcode == 0 + + def run_hook( + hook: Hook, + file_args: Sequence[str], + color: bool, + ) -> Tuple[int, bytes]: + with in_env(hook.prefix, hook.language_version): + return helpers.run_xargs(hook, hook.cmd, file_args, color=color) + + def install_environment( + prefix: Prefix, + version: str, + additional_dependencies: Sequence[str], + ) -> None: + additional_dependencies = tuple(additional_dependencies) + directory = helpers.environment_dir(_dir, version) + + env_dir = prefix.path(directory) + with clean_path_on_failure(env_dir): + if version != C.DEFAULT: + python = norm_version(version) + else: + python = os.path.realpath(sys.executable) + _make_venv(env_dir, python) + with in_env(prefix, version): + helpers.run_setup_cmd( + prefix, ('pip', 'install', '.') + additional_dependencies, + ) + + return in_env, healthy, run_hook, install_environment + + +def make_venv(envdir: str, python: str) -> None: + env = dict(os.environ, VIRTUALENV_NO_DOWNLOAD='1') + cmd = (sys.executable, '-mvirtualenv', envdir, '-p', python) + cmd_output_b(*cmd, env=env, cwd='/') + + +_interface = py_interface(ENVIRONMENT_DIR, make_venv) +in_env, healthy, run_hook, install_environment = _interface |