fixup shell (#786)

* fixup shell

* dont need to cover repr

Co-authored-by: MarcoGorelli <>

nbqa/__main__.py

@@ -2,6 +2,7 @@
 import itertools
 import os
 import re
+import shlex
 import string
 import subprocess
 import sys
@@ -301,7 +302,8 @@ def _run_command(
 
     if shell:
         # We already checked that which does not return None
-        cmd = [cast(str, which(main_command)), *sub_commands]
+
+        cmd = [cast(str, which(main_command)), *shlex.split(" ".join(sub_commands))]
     else:
         python_module = COMMAND_TO_PYTHON_MODULE.get(main_command, main_command)
         cmd = [sys.executable, "-m", python_module, *sub_commands]

nbqa/cmdline.py

@@ -86,6 +86,10 @@ def __init__(self, args: argparse.Namespace, cmd_args: Sequence[str]) -> None:
         self.md = args.nbqa_md or None
         self.shell = args.nbqa_shell or None
 
+    def __repr__(self) -> str:  # pragma: nocover
+        """Print prettily."""
+        return str(self.__dict__)
+
     @staticmethod
     def parse_args(argv: Optional[Sequence[str]]) -> "CLIArgs":
         """

tests/test_nbqa_shell.py

@@ -65,3 +65,11 @@ def test_nbqa_shell_not_found(monkeypatch: MonkeyPatch) -> None:
     msg = "\x1b\\[1mnbqa was unable to find some-fictional-command.\x1b\\[0m"
     with pytest.raises(CommandNotFoundError, match=msg):
         main(args)
+
+
+@pytest.mark.skipif(sys.platform != "linux", reason="needs grep")
+def test_grep(capsys: CaptureFixture) -> None:
+    """Check grep with string works."""
+    main(["grep 'import pandas'", ".", "--nbqa-shell"])
+    out, _ = capsys.readouterr()
+    assert out == "tests/data/notebook_for_autoflake.ipynb:import pandas as pd\n"