version argument in command line jupytext #103

jupytext/cli.py

@@ -9,6 +9,7 @@
 from .combine import combine_inputs_with_outputs
 from .compare import test_round_trip_conversion, NotebookDifference
 from .languages import _SCRIPT_EXTENSIONS
+from .version import __version__
 
 
 def convert_notebook_files(nb_files, fmt, input_format=None, output=None,
@@ -170,8 +171,13 @@ def cli_jupytext(args=None):
                            'round trip conversion')
     parser.add_argument('-x', '--stop', dest='stop_on_first_error', action='store_true',
                         help='Stop on first round trip conversion error, and report stack traceback')
+    parser.add_argument('--version', action='store_true',
+                        help="Show jupytext's version number and exit")
     args = parser.parse_args(args)
 
+    if args.version:
+        return args
+
     args.to = canonize_format(args.to, args.output)
 
     if args.input_format:
@@ -193,6 +199,11 @@ def jupytext(args=None):
     """Entry point for the jupytext script"""
     try:
         args = cli_jupytext(args)
+
+        if args.version:
+            sys.stdout.write(__version__)
+            return
+
         convert_notebook_files(nb_files=args.notebooks,
                                fmt=args.to,
                                input_format=args.input_format,

tests/test_cli.py

@@ -4,7 +4,7 @@
 from testfixtures import compare
 import mock
 from nbformat.v4.nbbase import new_notebook
-from jupytext import header
+from jupytext import header, __version__
 from jupytext import readf, writef, writes
 from jupytext.cli import convert_notebook_files, cli_jupytext, jupytext
 from jupytext.compare import compare_notebooks
@@ -55,6 +55,14 @@ def test_convert_single_file(nb_file, capsys):
     compare(out, pynb)
 
 
+def test_jupytext_version(capsys):
+    jupytext(['--version'])
+
+    out, err = capsys.readouterr()
+    assert err == ''
+    compare(out, __version__)
+
+
 @pytest.mark.parametrize('nb_file', list_notebooks('ipynb_cpp'))
 def test_to_cpluplus(nb_file, capsys):
     nb1 = readf(nb_file)