Applied changes from review

jupyter_core/command.py

@@ -15,7 +15,7 @@
 import sys
 from subprocess import Popen
 
-from distutils.spawn import find_executable
+from .utils.shutil_which import which
 
 from . import paths
 from .version import __version__
@@ -115,19 +115,24 @@ def _execvp(cmd, argv):
         os.execvp(cmd, argv)
 
 
-def _jupyter_realpath(path, subcommand):
-    # get currrent PATH
-    _path_env = os.environ['PATH']
-    # set new PATH with self
-    os.environ['PATH'] = os.pathsep.join(_path_with_self())
-    # get the real path for the jupyter-<subcommand>
-    real_path = find_executable('{}-{}'.format(path, subcommand))
-    # RESTORE previous PATH
-    os.environ['PATH'] = _path_env
-    return (
-        real_path if real_path is not None and os.access(real_path, os.X_OK)
-        else None
-    )
+def _jupyter_abspath(path, subcommand):
+    """This method get the abspath of jupyter with no changes on ENV."""
+    # get env PATH with self
+    search_path = os.pathsep.join(_path_with_self())
+    # get the abs path for the jupyter-<subcommand>
+    jupyter_subcommand = '{}-{}'.format(path, subcommand)
+    abs_path = which(jupyter_subcommand, path=search_path)
+    if abs_path is None:
+        raise Exception(
+            'Jupyter command `{}` not found.'.format(jupyter_subcommand)
+        )
+
+    if not os.access(abs_path, os.X_OK):
+        raise Exception(
+            'Jupyter command `{}` is not executable.'.format(jupyter_subcommand)
+        )
+
+    return abs_path
 
 
 def _path_with_self():
@@ -216,7 +221,7 @@ def main():
         parser.print_usage(file=sys.stderr)
         sys.exit("subcommand is required")
 
-    command = _jupyter_realpath(sys.argv[0], subcommand)
+    command = _jupyter_abspath(sys.argv[0], subcommand)
 
     try:
         _execvp(command, sys.argv[1:])