add has_ functions to the Python API

python/test/test_api.py

@@ -41,7 +41,6 @@ except:
 
 
 # create TREXIO file and open it for writing
-#test_file = trexio.open(output_filename, 'w', TEST_TREXIO_BACKEND)
 test_file = trexio.File(output_filename, mode='w', back_end=TEST_TREXIO_BACKEND)
 
 # Print docstring of the trexio.open function
@@ -65,7 +64,7 @@ warnings.filterwarnings("error")
 try:
     trexio.write_nucleus_num(test_file, nucleus_num*2)
 except UserWarning:
-    print("Attemp to overwrite nucleus_num: checked.")
+    print("Attempt to overwrite nucleus_num: checked.")
 
 # initialize charge arrays as a list and convert it to numpy array
 charges = [6., 6., 6., 6., 6., 6., 1., 1., 1., 1., 1., 1.]
@@ -127,22 +126,28 @@ labels = [
 trexio.write_nucleus_label(test_file,labels)
 
 # close TREXIO file 
-# [TODO:] this functional call is no longer needed as we introduced TREXIO_File class which has a desctructor that closes the file
+# this call is no longer needed as we introduced TREXIO_File class which has a desctructor that closes the file
 #trexio.close(test_file)
-# [TODO:] without calling destructor on test_file the TREXIO_FILE is not getting created and the data is not written when using TEXT back end. This, the user still has to explicitly call destructor on test_file object instead 
-# trexio.close function. This is only an issue when the data is getting written and read in the same session (e.g. in Jupyter notebook)
+# without calling destructor on test_file the TREXIO_FILE is not getting created and the data is not written when using TEXT back end. 
+# This, the user still has to explicitly call destructor on test_file object instead of the trexio.close function. 
+# This is only an issue when the data is getting written and read in the same session (e.g. in Jupyter notebook)
 del test_file
 
 
-
 #==========================================================#
 #============ READ THE DATA FROM THE TEST FILE ============#
 #==========================================================#
 
 # open previously created TREXIO file, now in 'read' mode
-#test_file2 = trexio.open(output_filename, 'r', TEST_TREXIO_BACKEND)
 test_file2 = trexio.File(output_filename, 'r', TEST_TREXIO_BACKEND)
 
+# check for existence of some of the previously written variables
+assert trexio.has_nucleus_num
+assert trexio.has_nucleus_charge
+assert trexio.has_nucleus_coord
+assert trexio.has_nucleus_label
+assert trexio.has_nucleus_point_group
+
 # read nucleus_num from file
 rnum = trexio.read_nucleus_num(test_file2)
 assert rnum==nucleus_num
@@ -194,6 +199,12 @@ for i in range(nucleus_num):
 rpoint_group = trexio.read_nucleus_point_group(test_file2)
 assert rpoint_group==point_group 
 
+# another way to read only if the variable exists
+if trexio.has_mo_num(test_file2):
+    rmo_num = trexio.read_mo_num(test_file2)
+else:
+    print("Not reading the non-existing variable mo_num.")
+
 # close TREXIO file
 #trexio.close(test_file2)
 

src/templates_front/templator_front.org

@@ -1444,6 +1444,33 @@ def read_$group_num$(trexio_file) -> int:
     return num_r
      #+end_src
 
+     #+begin_src python :tangle has_num_front.py
+def has_$group_num$(trexio_file) -> bool: 
+    """Check that $group_num$ variable exists in the TREXIO file.
+
+    Parameter is a ~TREXIO File~ object that has been created by a call to ~open~ function.
+
+    Returns:
+          True if the variable exists, False otherwise
+
+    Raises:
+        - Exception from trexio.Error class if TREXIO return code ~rc~ is TREXIO_FAILURE and prints the error message using string_of_error.
+        - Exception from some other error (e.g. RuntimeError).
+    """
+
+    try:
+        rc = pytr.trexio_has_$group_num$(trexio_file.pytrexio_s)
+        if rc == TREXIO_FAILURE:
+            raise Error(rc)
+    except:
+        raise    
+
+    if rc == TREXIO_SUCCESS:
+        return True
+    else:
+        return False
+     #+end_src
+
 ** Templates for front end has/read/write a dataset of numerical data
 
    This section concerns API calls related to datasets.
@@ -2148,6 +2175,34 @@ def read_$group_dset$(trexio_file, dim = None, doReshape = None, dtype = None):
     else:
         return dset_64
      #+end_src
+
+     #+begin_src python :tangle has_dset_data_front.py
+def has_$group_dset$(trexio_file) -> bool: 
+    """Check that $group_dset$ variable exists in the TREXIO file.
+
+    Parameter is a ~TREXIO File~ object that has been created by a call to ~open~ function.
+
+    Returns:
+          True if the variable exists, False otherwise
+
+    Raises:
+        - Exception from trexio.Error class if TREXIO return code ~rc~ is TREXIO_FAILURE and prints the error message using string_of_error.
+        - Exception from some other error (e.g. RuntimeError).
+    """
+
+    try:
+        rc = pytr.trexio_has_$group_dset$(trexio_file.pytrexio_s)
+        if rc == TREXIO_FAILURE:
+            raise Error(rc)
+    except:
+        raise    
+
+    if rc == TREXIO_SUCCESS:
+        return True
+    else:
+        return False
+     #+end_src
+
 ** Sparse data structures
 
    Sparse data structures are used typically for large tensors such as
@@ -2693,6 +2748,34 @@ def read_$group_dset$(trexio_file, dim = None) -> list:
 
     return dset_2d_r
      #+end_src
+
+     #+begin_src python :tangle has_dset_str_front.py
+def has_$group_dset$(trexio_file) -> bool: 
+    """Check that $group_dset$ variable exists in the TREXIO file.
+
+    Parameter is a ~TREXIO File~ object that has been created by a call to ~open~ function.
+
+    Returns:
+          True if the variable exists, False otherwise
+
+    Raises:
+        - Exception from trexio.Error class if TREXIO return code ~rc~ is TREXIO_FAILURE and prints the error message using string_of_error.
+        - Exception from some other error (e.g. RuntimeError).
+    """
+
+    try:
+        rc = pytr.trexio_has_$group_dset$(trexio_file.pytrexio_s)
+        if rc == TREXIO_FAILURE:
+            raise Error(rc)
+    except:
+        raise    
+
+    if rc == TREXIO_SUCCESS:
+        return True
+    else:
+        return False
+     #+end_src
+
 ** Templates for front end has/read/write a single string attribute
 *** Introduction
 
@@ -2932,6 +3015,33 @@ def read_$group_str$(trexio_file) -> str:
     return str_r
      #+end_src
      
+     #+begin_src python :tangle has_attr_str_front.py
+def has_$group_str$(trexio_file) -> bool: 
+    """Check that $group_str$ variable exists in the TREXIO file.
+
+    Parameter is a ~TREXIO File~ object that has been created by a call to ~open~ function.
+
+    Returns:
+          True if the variable exists, False otherwise
+
+    Raises:
+        - Exception from trexio.Error class if TREXIO return code ~rc~ is TREXIO_FAILURE and prints the error message using string_of_error.
+        - Exception from some other error (e.g. RuntimeError).
+    """
+
+    try:
+        rc = pytr.trexio_has_$group_str$(trexio_file.pytrexio_s)
+        if rc == TREXIO_FAILURE:
+            raise Error(rc)
+    except:
+        raise    
+
+    if rc == TREXIO_SUCCESS:
+        return True
+    else:
+        return False
+     #+end_src
+
 * Fortran helper/wrapper functions
 
   The function below adapts the original C-based ~trexio_open~ for Fortran.