ENH: Refactor the dataset parameters tuples

Refactor the dataset parameters tuples:
- The dataset tuples do not provide an effective fetcher, but only the
parameters needed to make the fetcher. Thus, the `fetcher_` prefix is
removed.
- Rename the method that provides the fetcher parameters accordingly.
- The fetcher names are all built in the same way, and thus this is put
into a method for the sake of best coding practices. Also, prefer naming
the fetchers directly using the Dataset enum values.

tractolearn/tractoio/dataset_fetch.py

@@ -329,8 +329,7 @@ def fetcher():
     return fetcher
 
 
-fetch_bundle_label_config = (
-    "fetch_bundle_label_config",
+bundle_label_config = (
     TRACTOLEARN_DATASETS_URL + "/7562790/files/",
     ["rbx_atlas_v10.json"],
     ["rbx_atlas_v10.json"],
@@ -341,8 +340,7 @@ def fetcher():
     False,
 )
 
-fetch_contrastive_ae_weights = (
-    "fetch_contrastive_ae_weights",
+contrastive_ae_weights = (
     TRACTOLEARN_DATASETS_URL + "7562790/files/",
     ["best_model_contrastive_tractoinferno_hcp.pt"],
     ["best_model_contrastive_tractoinferno_hcp.pt"],
@@ -353,8 +351,7 @@ def fetcher():
     False,
 )
 
-fetch_mni2009cnonlinsymm_anat = (
-    "fetch_mni2009cnonlinsymm_anat",
+mni2009cnonlinsymm_anat = (
     TRACTOLEARN_DATASETS_URL + "7562790/files/",
     ["mni_masked.nii.gz"],
     ["mni_masked.nii.gz"],
@@ -365,8 +362,7 @@ def fetcher():
     False,
 )
 
-fetch_generative_loa_cone_config = (
-    "fetch_generative_loa_cone_config",
+generative_loa_cone_config = (
     TRACTOLEARN_DATASETS_URL + "/7562790/files/",
     ["degree.json"],
     ["degree.json"],
@@ -377,8 +373,7 @@ def fetcher():
     False,
 )
 
-fetch_generative_seed_streamline_ratio_config = (
-    "fetch_generative_seed_streamline_ratio_config",
+generative_seed_streamline_ratio_config = (
     TRACTOLEARN_DATASETS_URL + "/7562790/files/",
     ["ratio.json"],
     ["ratio.json"],
@@ -389,8 +384,7 @@ def fetcher():
     False,
 )
 
-fetch_generative_streamline_max_count_config = (
-    "fetch_generative_streamline_max_count_config",
+generative_streamline_max_count_config = (
     TRACTOLEARN_DATASETS_URL + "/7562790/files/",
     ["max_total_sampling.json"],
     ["max_total_sampling.json"],
@@ -401,8 +395,7 @@ def fetcher():
     False,
 )
 
-fetch_generative_streamline_req_count_config = (
-    "fetch_generative_streamline_req_count_config",
+generative_streamline_req_count_config = (
     TRACTOLEARN_DATASETS_URL + "/7562790/files/",
     ["number_rejection_sampling.json"],
     ["number_rejection_sampling.json"],
@@ -413,8 +406,7 @@ def fetcher():
     False,
 )
 
-fetch_generative_wm_tisue_criterion_config = (
-    "fetch_generative_wm_tisue_criterion_config",
+generative_wm_tisue_criterion_config = (
     TRACTOLEARN_DATASETS_URL + "/7562790/files/",
     ["white_matter_mask.json"],
     ["white_matter_mask.json"],
@@ -425,8 +417,7 @@ def fetcher():
     False,
 )
 
-fetch_recobundlesx_atlas = (
-    "fetch_recobundlesx_atlas",
+recobundlesx_atlas = (
     TRACTOLEARN_DATASETS_URL + "7562635/files/",
     ["atlas.zip"],
     ["atlas.zip"],
@@ -437,8 +428,7 @@ def fetcher():
     True,
 )
 
-fetch_recobundlesx_config = (
-    "fetch_recobundlesx_config",
+recobundlesx_config = (
     TRACTOLEARN_DATASETS_URL + "7562635/files/",
     ["config.zip"],
     ["config.zip"],
@@ -449,8 +439,7 @@ def fetcher():
     True,
 )
 
-fetch_tractoinferno_hcp_contrastive_threshold_config = (
-    "fetch_tractoinferno_hcp_contrastive_threshold_config",
+tractoinferno_hcp_contrastive_threshold_config = (
     TRACTOLEARN_DATASETS_URL + "/7562790/files/",
     ["thresholds_contrastive_tractoinferno_hcp.json"],
     ["thresholds_contrastive_tractoinferno_hcp.json"],
@@ -461,8 +450,7 @@ def fetcher():
     False,
 )
 
-fetch_tractoinferno_hcp_ref_tractography = (
-    "fetch_tractoinferno_hcp_ref_tractography",
+tractoinferno_hcp_ref_tractography = (
     TRACTOLEARN_DATASETS_URL + "/7562790/files/",
     ["data_tractoinferno_hcp_qbx.hdf5"],
     ["data_tractoinferno_hcp_qbx.hdf5"],
@@ -474,43 +462,59 @@ def fetcher():
 )
 
 
-def get_fetcher_method(name):
-    """Provide the fetcher method corresponding to the method name.
+def _get_fetcher_data(name):
+    """Provide the fetcher method parameters corresponding to the method name.
 
     Returns
     -------
-    callable
-        Fetcher method.
+    Tuple
+        Fetcher method parameters.
     """
 
     if name == Dataset.BUNDLE_LABEL_CONFIG.name:
-        return fetch_bundle_label_config
+        return bundle_label_config
     elif name == Dataset.CONTRASTIVE_AUTOENCODER_WEIGHTS.name:
-        return fetch_contrastive_ae_weights
+        return contrastive_ae_weights
     elif name == Dataset.MNI2009CNONLINSYMM_ANAT.name:
-        return fetch_mni2009cnonlinsymm_anat
+        return mni2009cnonlinsymm_anat
     elif name == Dataset.GENERATIVE_LOA_CONE_CONFIG.name:
-        return fetch_generative_loa_cone_config
+        return generative_loa_cone_config
     elif name == Dataset.GENERATIVE_SEED_STRML_RATIO_CONFIG.name:
-        return fetch_generative_seed_streamline_ratio_config
+        return generative_seed_streamline_ratio_config
     elif name == Dataset.GENERATIVE_STRML_MAX_COUNT_CONFIG.name:
-        return fetch_generative_streamline_max_count_config
+        return generative_streamline_max_count_config
     elif name == Dataset.GENERATIVE_STRML_RQ_COUNT_CONFIG.name:
-        return fetch_generative_streamline_req_count_config
+        return generative_streamline_req_count_config
     elif name == Dataset.GENERATIVE_WM_TISSUE_CRITERION_CONFIG.name:
-        return fetch_generative_wm_tisue_criterion_config
+        return generative_wm_tisue_criterion_config
     elif name == Dataset.RECOBUNDLESX_ATLAS.name:
-        return fetch_recobundlesx_atlas
+        return recobundlesx_atlas
     elif name == Dataset.RECOBUNDLESX_CONFIG.name:
-        return fetch_recobundlesx_config
+        return recobundlesx_config
     elif name == Dataset.TRACTOINFERNO_HCP_CONTRASTIVE_THR_CONFIG.name:
-        return fetch_tractoinferno_hcp_contrastive_threshold_config
+        return tractoinferno_hcp_contrastive_threshold_config
     elif name == Dataset.TRACTOINFERNO_HCP_REF_TRACTOGRAPHY.name:
-        return fetch_tractoinferno_hcp_ref_tractography
+        return tractoinferno_hcp_ref_tractography
     else:
         raise DatasetError(_unknown_dataset_msg(name))
 
 
+def _compose_fetcher_name(name):
+    """Compose a name for the fetcher given the dataset name.
+
+    Parameters
+    ----------
+    name : string
+        Dataset name.
+    Returns
+    -------
+    string
+        Fetcher name for dataset.
+    """
+
+    return "fetcher_" + Dataset[name].value
+
+
 def provide_dataset_description():
     """Provide the description of the available datasets.
 
@@ -525,7 +529,7 @@ def provide_dataset_description():
     descr = list()
 
     for elem in list(Dataset):
-        params = get_fetcher_method(elem.name)
+        params = _get_fetcher_data(elem.name)
         descr.append(
             elem.value
             + ": "
@@ -556,8 +560,9 @@ def retrieve_dataset(name, path):
 
     logger.info(f"\nDataset: {name}")
 
-    params = get_fetcher_method(name)
-    files, folder = _make_fetcher(path, *params)()
+    params = _get_fetcher_data(name)
+    fetcher_name = _compose_fetcher_name(name)
+    files, folder = _make_fetcher(path, fetcher_name, *params)()
 
     file_basename = list(files.keys())[0]