Fix "Executable" class

kiwi_scp/executable.py

@@ -1,74 +1,60 @@
-# system
+import functools
 import logging
 import os
 import subprocess
+from pathlib import Path
+from typing import Optional, List, Any
+
+import attr
+
+_logger = logging.getLogger(__name__)
 
 
-def _is_executable(filename):
-    if filename is None:
-        return False
-
-    return os.path.isfile(filename) and os.access(filename, os.X_OK)
-
-
-def _find_exe_file(exe_name):
-    for path in os.environ['PATH'].split(os.pathsep):
-        exe_file = os.path.join(path, exe_name)
-        if _is_executable(exe_file):
-            return exe_file
-
-    raise FileNotFoundError(f"Executable '{exe_name}' not found in $PATH!")
-
-
+@attr.s
 class Executable:
-    class __Executable:
-        __exe_path = None
+    exe_name: str = attr.ib()
 
-        def __init__(self, exe_name):
-            self.__exe_path = _find_exe_file(exe_name)
+    @staticmethod
+    @functools.lru_cache(maxsize=None)
+    def __find_exe_file(exe_name: str) -> Optional[Path]:
+        for path in os.environ['PATH'].split(os.pathsep):
+            exe_file = Path(path).joinpath(exe_name)
+            if os.path.isfile(exe_file) and os.access(exe_file, os.X_OK):
+                return exe_file
 
-        def __build_cmd(self, args, kwargs):
-            cmd = [self.__exe_path, *args]
+        raise FileNotFoundError(f"Executable '{exe_name}' not found in $PATH!")
 
-            logging.debug(f"Executable cmd{cmd}, kwargs{kwargs}")
-            return cmd
+    @property
+    def exe_file(self) -> Optional[Path]:
+        return self.__find_exe_file(self.exe_name)
 
-        def run(self, process_args, **kwargs):
-            return subprocess.run(
-                self.__build_cmd(process_args, kwargs),
-                **kwargs
-            )
+    def __build_cmd(self, args, kwargs) -> List[Path, Any, ...]:
+        cmd = [self.exe_file, *args]
 
-        def Popen(self, process_args, **kwargs):
-            return subprocess.Popen(
-                self.__build_cmd(process_args, kwargs),
-                **kwargs
-            )
+        _logger.debug(f"Executable cmd{cmd}, kwargs{kwargs}")
+        return cmd
 
-        def run_less(self, process_args, **kwargs):
-            kwargs['stdout'] = subprocess.PIPE
-            kwargs['stderr'] = subprocess.DEVNULL
+    def run(self, process_args, **kwargs) -> Optional[subprocess.CompletedProcess]:
+        return subprocess.run(
+            self.__build_cmd(process_args, kwargs),
+            **kwargs
+        )
 
-            process = self.Popen(
-                process_args,
-                **kwargs
-            )
+    def Popen(self, process_args, **kwargs) -> subprocess.Popen[str]:
+        return subprocess.Popen(
+            self.__build_cmd(process_args, kwargs),
+            **kwargs
+        )
 
+    def run_less(self, process_args, **kwargs) -> Optional[subprocess.CompletedProcess]:
+        kwargs['stdout'] = subprocess.PIPE
+        kwargs['stderr'] = subprocess.DEVNULL
+
+        with self.Popen(process_args, **kwargs) as process:
             less_process = Executable('less').run([
                 '-R', '+G'
             ], stdin=process.stdout)
 
             process.communicate()
-            return less_process
 
-    __exe_name = None
-    __instances = {}
-
-    def __init__(self, exe_name):
-        self.__exe_name = exe_name
-
-        if exe_name not in Executable.__instances:
-            Executable.__instances[exe_name] = Executable.__Executable(exe_name)
-
-    def __getattr__(self, item):
-        return getattr(self.__instances[self.__exe_name], item)
+        return less_process