closes #29: initial commit on load datetime of the analysis

src/diffpy/labpdfproc/labpdfprocapp.py

@@ -89,6 +89,15 @@ def get_args(override_cli_inputs=None):
         "For example, facility='NSLS II', 'facility=NSLS II', beamline=28ID-2, "
         "'beamline'='28ID-2', 'favorite color'=blue, are all valid key=value items. ",
     )
+    p.add_argument(
+        "-d"
+        "--datetime_of_analysis",
+        metavar="YYYY-MM-DD HH:MI:SS",
+        help=f"The date and time of the analysis. Required."
+             "The format should be in YYYY-MM-DD HH:MM:SS format.",
+    )
+    args = p.parse_args(override_cli_inputs)
+    return args
     args = p.parse_args(override_cli_inputs)
     return args
 

src/diffpy/labpdfproc/tests/test_tools.py

@@ -1,7 +1,7 @@
 import os
 import re
 from pathlib import Path
-
+from datetime import datetime
 import pytest
 
 from diffpy.labpdfproc.labpdfprocapp import get_args
@@ -11,7 +11,7 @@
     load_user_metadata,
     set_input_lists,
     set_output_directory,
-    set_wavelength,
+    set_wavelength, load_datetime,
 )
 
 # Use cases can be found here: https://github.com/diffpy/diffpy.labpdfproc/issues/48
@@ -232,3 +232,35 @@ def test_load_user_metadata_bad(inputs, msg):
     actual_args = get_args(cli_inputs)
     with pytest.raises(ValueError, match=msg[0]):
         actual_args = load_user_metadata(actual_args)
+
+
+params7 = [(["--datetime-of-analysis", "2020-02-02 00:00:00"],
+            ["--user-metadata", f"datetime={datetime.strptime("2020-02-02 00:00:00", "%Y-%m-%d %H:%M:%S")}"]),
+           (["--datetime-of-analysis", "2022-03-28 02:15:34"],
+            ["--user-metadata", f"datetime={datetime.strptime("2022-03-28 02:15:34", "%Y-%m-%d %H:%M:%S")}"]),
+           (["--datetime-of-analysis", "2022-03-30 23:15:44"],
+            ["--user-metadata", f"datetime={datetime.strptime("2022-03-28 02:15:34", "%Y-%m-%d %H:%M:%S")}"])]
+
+
+@pytest.mark.parametrize("inputs, expected", params7)
+def test_load_datetime(inputs, expected):
+    cli_inputs = ["2.5"] + inputs
+    actual_args = get_args(cli_inputs)
+    expected_datetime = expected[0]
+    actual_datetime = load_datetime(actual_args)
+    assert actual_datetime == expected_datetime
+
+
+params8 = [(["--datetime-of-analysis", "2020-13-01 02:15:34"],
+            ["Please provide a valid datetime value. For more information, use `labpdfproc --help.`"]),
+           (["--datetime-of-analysis", "nqpk-nn-01 02:15:34"],
+            ["Please provide a valid datetime value. For more information, use `labpdfproc --help.`"]),
+           (["--datetime-of-analysis", "2025-12-01 02:15:34"], ["Future date entered. Please enter a valid date."])]
+
+
+@pytest.mark.parametrize("inputs, expected", params8)
+def test_load_datetime_bad(inputs, expected):
+    cli_inputs = ["2.5", "data.xy"] + inputs
+    actual_args = get_args(cli_inputs)
+    with pytest.raises(ValueError, match=expected[0]):
+        load_datetime(actual_args)

src/diffpy/labpdfproc/tools.py

@@ -1,5 +1,5 @@
 from pathlib import Path
-
+from datetime import datetime
 WAVELENGTHS = {"Mo": 0.71, "Ag": 0.59, "Cu": 1.54}
 known_sources = [key for key in WAVELENGTHS.keys()]
 
@@ -165,3 +165,31 @@ def load_user_metadata(args):
             setattr(args, key, value)
     delattr(args, "user_metadata")
     return args
+
+
+def load_datetime(args):
+    """
+    Load the datetime of analysis into Metadata.
+
+    Parameters
+    ----------
+    args argparse.Namespace
+        the arguments from the parser
+
+
+    Returns
+    -------
+    the updated argparse Namespace with datetime object.
+
+    """
+    try:
+        input_date = datetime.strptime(args.datetime, '%Y-%m-%d %H:%M:%S').date()
+        current_date = datetime.now().date()
+        if input_date > current_date:
+            raise ValueError("Future date entered. Please enter a valid date.")
+        datetime_obj = datetime.strptime(args.datetime, "%Y-%m-%d %H:%M:%S")
+        user_metadata = load_user_metadata(args)
+        user_metadata.update({"datetime": datetime_obj})
+        return user_metadata
+    except ValueError:
+        raise ValueError("Please provide a valid datetime value. For more information, use `labpdfproc --help.`")