From 729ff1af65330923116fc91ef0e38ae43c5b3311 Mon Sep 17 00:00:00 2001
From: Philippe THOMY <philippe@loco-labs.io>
Date: Fri, 17 May 2024 15:12:34 +0200
Subject: [PATCH] xarray accessors

---
 ntv_numpy/xarray_accessors.py | 52 +++++++++++++++++++++++++++++++++++
 ntv_numpy/xconnector.py       |  5 ++--
 ntv_numpy/xdataset.py         |  6 ++--
 3 files changed, 57 insertions(+), 6 deletions(-)
 create mode 100644 ntv_numpy/xarray_accessors.py

diff --git a/ntv_numpy/xarray_accessors.py b/ntv_numpy/xarray_accessors.py
new file mode 100644
index 0000000..f3e920b
--- /dev/null
+++ b/ntv_numpy/xarray_accessors.py
@@ -0,0 +1,52 @@
+# -*- coding: utf-8 -*-
+"""
+The `xarray_accessors` module is part of the `ntv-numpy.ntv_numpy` package.
+
+It contains the class `NnpDatasetAccessors`.
+
+For more information, see the
+[user guide](https://loco-philippe.github.io/ntv-numpy/docs/user_guide.html)
+ or the [github repository](https://github.com/loco-philippe/ntv-numpy).
+"""
+import xarray as xr
+
+from ntv_numpy.xdataset import Xdataset
+
+try:
+    # delete the accessor to avoid warning
+    del xr.Dataset.nnp
+except AttributeError:
+    pass
+
+@xr.register_dataset_accessor("nnp")
+class NnpDatasetAccessor:
+    """Accessor class for methods invoked as `xr.Dataset.nnp.*`"""
+    
+    def __init__(self, xarray_obj):
+        '''initialisation of the class'''
+        self._obj = xarray_obj
+
+    def to_dataframe(self, **kwargs):
+        """Accessor for method `Xdataset.from_xarray.to_dataframe` invoked as
+        xr.Dataset.nnp.to_dataframe`.
+
+        *Parameters*
+
+        - **ntv_type**: Boolean (default True) - if False use full_name else json_name
+        - **info**: Boolean (default True) - if True add xdt.info in DataFrame.attrs
+        - **dims**: list of string (default None) - order of dimensions full_name to apply
+        - **index**: Boolean (default True) - if True, dimensions are translated into indexes
+        """
+        return Xdataset.from_xarray(self._obj, **kwargs).to_dataframe(**kwargs)
+
+    def to_scipp(self, **kwargs):
+        """Accessor for method `Xdataset.from_xarray.to_scipp` invoked as
+        xr.Dataset.nnp.to_scipp`.
+
+        *Parameters*
+
+        - **ntv_type**: Boolean (default True) - if False use full_name else json_name
+        - **info**: Boolean (default True) - if True add xdt.info in DataFrame.attrs
+        - **dims**: list of string (default None) - order of dimensions full_name to apply
+        """
+        return Xdataset.from_xarray(self._obj, **kwargs).to_scipp(**kwargs)
diff --git a/ntv_numpy/xconnector.py b/ntv_numpy/xconnector.py
index 67a481f..a666c36 100644
--- a/ntv_numpy/xconnector.py
+++ b/ntv_numpy/xconnector.py
@@ -95,8 +95,9 @@ def xexport(xdt, **kwargs):
         - **ntv_type**: Boolean (default True) - if False use full_name else json_name
         - **info**: Boolean (default True) - if True add xdt.info in DataFrame.attrs
         - **dims**: list of string (default None) - order of dimensions full_name to apply
+        - **index**: Boolean (default True) - if True, dimensions are translated into indexes
         '''
-        opt = {'ntv_type': True, 'info': True, 'dims': None} | kwargs
+        opt = {'ntv_type': True, 'info': True, 'index': True, 'dims': None} | kwargs
         dic_name = {name: xdt[name].json_name if opt['ntv_type'] else xdt[name].full_name
                     for name in xdt.names}
         dims = xdt.dimensions if not opt['dims'] else tuple(opt['dims'])
@@ -109,7 +110,7 @@ def xexport(xdt, **kwargs):
                       for name in fields_array}
         dfr = pd.DataFrame(dic_series)
         index = [dic_name[name] for name in dims]
-        if index:
+        if index and opt['index']:
             dfr = dfr.set_index(index)
         if opt['info']:
             dfr.attrs |= {'info': xdt.tab_info}
diff --git a/ntv_numpy/xdataset.py b/ntv_numpy/xdataset.py
index 40cda8c..2a19221 100644
--- a/ntv_numpy/xdataset.py
+++ b/ntv_numpy/xdataset.py
@@ -1,9 +1,6 @@
 # -*- coding: utf-8 -*-
 """
-@author: Philippe@loco-labs.io
-
-The `xdataset` module is part of the `ntv-numpy.ntv_numpy` package ([specification document](
-https://loco-philippe.github.io/ES/JSON%20semantic%20format%20(JSON-NTV).htm)).
+The `xdataset` module is part of the `ntv-numpy.ntv_numpy` package.
 
 It contains the classes `Xdataset`, `XdatasetInterface`, `XdatasetCategory` for
 the multidimensional dataset.
@@ -231,6 +228,7 @@ def to_dataframe(self, **kwargs):
         - **ntv_type**: Boolean (default True) - if False use full_name else json_name
         - **info**: Boolean (default True) - if True add xdt.info in DataFrame.attrs
         - **dims**: list of string (default None) - order of dimensions full_name to apply
+        - **index**: Boolean (default True) - if True, dimensions are translated into indexes
         '''
         return PandasConnec.xexport(self, **kwargs)