Using argparse in CLI apps.

nbdime/nbdiffapp.py

@@ -8,6 +8,7 @@
 
 import os
 import sys
+import argparse
 import nbformat
 import json
 
@@ -16,18 +17,14 @@
 from .prettyprint import pretty_print_notebook_diff
 
 
-_usage = """\
-Compute the difference between two Jupyter notebooks.
+_description = "Compute the difference between two Jupyter notebooks."
 
-This is nbdiff from nbdime version {}.
 
-Example usage:
+def main_diff(args):
+    afn = args.base
+    bfn = args.remote
+    dfn = args.output
 
-  nbdiff before.ipynb after.ipynb patch.json
-""".format(__version__)
-
-
-def main_diff(afn, bfn, dfn=None):
     for fn in (afn, bfn):
         if not os.path.exists(fn):
             print("Missing file {}".format(fn))
@@ -55,12 +52,66 @@ def main_diff(afn, bfn, dfn=None):
     return 0
 
 
+# TODO: Reuse these add_*_args functions across the apps
+def add_generic_args(parser):
+    parser.add_argument('--version',
+                        action="version",
+                        version="%(prog)s " + __version__)
+    parser.add_argument('-o', '--output',
+                        default=None,
+                        help="the output filename.")
+    if 0:  # TODO: Use verbose and quiet across nbdime and enable these:
+        qv_group = parser.add_mutually_exclusive_group()
+        qv_group.add_argument('-v', '--verbose',
+                             default=False,
+                             action="store_true",
+                             help="increase verbosity of console output.")
+        qv_group.add_argument('-q', '--quiet',
+                              default=False,
+                              action="store_true",
+                              help="silence console output.")
+
+def add_webgui_args(parser):
+    parser.add_argument('-p', '--port',
+                        default=8888,
+                        type=int,
+                        help="specify the port you want the server "
+                             "to run on. Default is 8888.")
+    cwd = os.path.abspath(os.path.curdir)
+    parser.add_argument('-w', '--workdirectory',
+                        default=cwd,  # TODO: Are there any security implications of doing this?
+                        help="specify the working directory you want "
+                             "the server to run from. Default is the "
+                             "actual cwd at program start.")
+
+def add_diff_args(parser):
+    # TODO: Add diff strategy options that are reusable for the merge command here
+
+    # TODO: Define sensible strategy variables and implement
+    #parser.add_argument('-d', '--diff-strategy',
+    #                    default="default", choices=("foo", "bar"),
+    #                    help="specify the diff strategy to use.")
+    pass
+
+
+def _build_arg_parser():
+    """Creates an argument parser for the nbdiff command."""
+    parser = argparse.ArgumentParser(
+        description=_description,
+        add_help=True,
+        )
+    add_generic_args(parser)
+    #add_webgui_args(parser)
+    add_diff_args(parser)
+
+    parser.add_argument('base',
+                        help="the base notebook file.")
+    parser.add_argument('remote',
+                        help="the modified notebook file.")
+    return parser
+
+
 def main():
-    args = sys.argv[1:]
-    if len(args) not in (2, 3):
-        r = 1
-    else:
-        r = main_diff(*args)
-    if r:
-        print(_usage)
+    args = _build_arg_parser().parse_args()
+    r = main_diff(args)
     sys.exit(r)

nbdime/nbmergeapp.py

@@ -8,23 +8,21 @@
 
 import os
 import sys
+import argparse
 import nbformat
 from ._version import __version__
 from .merging import merge_notebooks
 
 
-_usage = """\
-Merge two Jupyter notebooks "local" and "remote" with a common ancestor "base".
+_description = 'Merge two Jupyter notebooks "local" and "remote" with a common ancestor "base".'
 
-This is nbmerge from nbdime version {}.
 
-Example usage:
+def main_merge(args):
+    bfn = args.base
+    lfn = args.local
+    rfn = args.remote
+    mfn = args.output
 
-  nbmerge base.ipynb local.ipynb remote.ipynb merged.ipynb
-""".format(__version__)
-
-
-def main_merge(bfn, lfn, rfn, mfn):
     for fn in (bfn, lfn, rfn):
         if not os.path.exists(fn):
             print("Cannot find file '{}'".format(fn))
@@ -66,12 +64,36 @@ def main_merge(bfn, lfn, rfn, mfn):
     return 0
 
 
+def _build_arg_parser():
+    """Creates an argument parser for the nbdiff command."""
+    parser = argparse.ArgumentParser(
+        description=_description,
+        add_help=True,
+        )
+    from .nbdiffapp import add_generic_args, add_webgui_args, add_diff_args
+    add_generic_args(parser)
+    #add_webgui_args(parser)
+    add_diff_args(parser)
+
+    # TODO: Define sensible strategy variables and implement
+    #parser.add_argument('-m', '--merge-strategy',
+    #                    default="default", choices=("foo", "bar"),
+    #                    help="Specify the merge strategy to use.")
+    parser.add_argument('-i', '--ignore-transients',
+                        action="store_true",
+                        default=False,
+                        help="Allow automatic deletion of transient data to resolve conflicts (output, execution count).")
+
+    parser.add_argument('base',
+                        help="The base notebook filename.")
+    parser.add_argument('local',
+                        help="The local modified notebook filename.")
+    parser.add_argument('remote',
+                        help="The remote modified notebook filename.")
+    return parser
+
+
 def main():
-    args = sys.argv[1:]
-    if len(args) != 4:
-        r = 1
-    else:
-        r = main_merge(*args)
-    if r:
-        print(_usage)
+    args = _build_arg_parser().parse_args()
+    r = main_merge(args)
     sys.exit(r)

nbdime/nbpatchapp.py

@@ -8,24 +8,21 @@
 
 import os
 import sys
-import nbformat
+import argparse
 import json
+import nbformat
 from ._version import __version__
 from .patching import patch_notebook
 from .diff_format import to_diffentry_dicts
 
-_usage = """\
-Apply patch from nbpatch to a Jupyter notebook.
-
-This is nbpatch from nbdime version {}.
-
-Example usage:
+_description = "Apply patch from nbpatch to a Jupyter notebook."
 
-  nbpatch before.ipynb patch.json after.ipynb
-""".format(__version__)
 
+def main_patch(args):
+    bfn = args.base
+    dfn = args.patch
+    afn = args.output
 
-def main_patch(bfn, dfn, afn):
     for fn in (bfn, dfn):
         if not os.path.exists(fn):
             print("Missing file {}".format(fn))
@@ -49,12 +46,23 @@ def main_patch(bfn, dfn, afn):
     return 0
 
 
+def _build_arg_parser():
+    """Creates an argument parser for the nbpatch command."""
+    parser = argparse.ArgumentParser(
+        description=_description,
+        add_help=True,
+        )
+    from .nbdiffapp import add_generic_args
+    add_generic_args(parser)
+
+    parser.add_argument('base',
+                        help="The base notebook filename.")
+    parser.add_argument('patch',
+                        help="The patch filename, output from nbdiff.")
+    return parser
+
+
 def main():
-    args = sys.argv[1:]
-    if len(args) != 3:
-        r = 1
-    else:
-        r = main_patch(*args)
-    if r:
-        print(_usage)
+    args = _build_arg_parser().parse_args()
+    r = main_patch(args)
     sys.exit(r)

nbdime/tests/test_cli_apps.py

@@ -3,9 +3,11 @@
 
 import pytest
 import os
+from argparse import Namespace
 
 from .fixtures import filespath
 
+import nbdime
 from nbdime.nbdiffapp import main_diff
 from nbdime.nbpatchapp import main_patch
 from nbdime.nbmergeapp import main_merge
@@ -15,25 +17,34 @@ def test_nbdiff_app():
     p = filespath()
     afn = os.path.join(p, "multilevel-test-base.ipynb")
     bfn = os.path.join(p, "multilevel-test-local.ipynb")
+
     # When filename is omitted, will print to console instead
-    dfn = ""  # os.path.join(p, "multilevel-test-local-diff.json")
-    assert 0 == main_diff(afn, bfn, dfn)
+    #dfn = ""  # os.path.join(p, "multilevel-test-local-diff.json")
+
+    args = nbdime.nbdiffapp._build_arg_parser().parse_args([afn, bfn])
+    assert 0 == main_diff(args)
 
 
 def test_nbpatch_app():
     p = filespath()
     bfn = os.path.join(p, "multilevel-test-base.ipynb")
     dfn = os.path.join(p, "multilevel-test-base-local-diff.json")
+
     # When filename is omitted, will print to console instead
-    afn = ""  # os.path.join(p, "multilevel-test-base-local.ipynb")
-    assert 0 == main_patch(bfn, dfn, afn)
+    #afn = ""  # os.path.join(p, "multilevel-test-base-local.ipynb")
+
+    args = nbdime.nbpatchapp._build_arg_parser().parse_args([bfn, dfn])
+    assert 0 == main_patch(args)
 
 
 def test_nbmerge_app():
     p = filespath()
     bfn = os.path.join(p, "multilevel-test-base.ipynb")
     lfn = os.path.join(p, "multilevel-test-local.ipynb")
     rfn = os.path.join(p, "multilevel-test-remote.ipynb")
+
     # When filename is omitted, will print to console instead
-    mfn = ""  # os.path.join(temppath, "multilevel-test-merged.ipynb")
-    assert 0 == main_merge(bfn, lfn, rfn, mfn)
+    #mfn = ""  # os.path.join(temppath, "multilevel-test-merged.ipynb")
+
+    args = nbdime.nbmergeapp._build_arg_parser().parse_args([bfn, lfn, rfn])
+    assert 0 == main_merge(args)