Add support for Python with statement

(see PEP 343 for more details)

python/test/test_api.py

@@ -32,7 +32,7 @@ try:
     elif TEST_TREXIO_BACKEND == trexio.TREXIO_TEXT:
         shutil.rmtree(output_filename)
 except:
-    print ('Nothing to remove.')
+    print('Nothing to remove.')
 
 #=========================================================#
 #============ WRITE THE DATA IN THE TEST FILE ============#
@@ -40,6 +40,17 @@ except:
 
 trexio.info()
 
+
+# test with ... as ... block
+with trexio.File(output_filename, mode='w', back_end=TEST_TREXIO_BACKEND) as tfile:
+    trexio.write_metadata_description(tfile, "Test file produced by the Python API")
+    assert trexio.has_metadata_description(tfile)
+    assert tfile.isOpen
+
+# the file handle can remain existing but the file itself is closed upon exit from the `with` block
+assert not tfile.isOpen
+
+
 # create TREXIO file and open it for writing
 test_file = trexio.File(output_filename, mode='w', back_end=TEST_TREXIO_BACKEND)
 assert test_file.exists
@@ -281,7 +292,7 @@ assert rpoint_group==point_group
 
 # another way to read only if the variable exists
 if trexio.has_ao_num(test_file2):
-    rmo_num = trexio.read_ao_num(test_file2)
+    rao_num = trexio.read_ao_num(test_file2)
 else:
     print("Pass on reading the non-existing variable ao_num: checked")
 
@@ -295,7 +306,7 @@ try:
    elif TEST_TREXIO_BACKEND == trexio.TREXIO_TEXT:
        shutil.rmtree(output_filename)
 except:
-    print (f'No output file {output_filename} has been produced')
+    print(f'No output file {output_filename} has been produced')
 
 #==========================================================#
 

src/templates_front/templator_front.org

@@ -720,8 +720,7 @@ class File:
 
     def __init__(self, filename, mode='r', back_end=TREXIO_HDF5,
                  pytrexio_s=None, info=None):
-        """This is a TREXIO File constructor."""
-
+        """TREXIO File class constructor."""
         self.filename = filename
         self.mode = mode
         self.back_end = back_end
@@ -740,9 +739,19 @@ class File:
         self.info = info
 
 
+    def __enter__(self):
+        """Enter statement for with ... as ... handling."""
+        return self
+
+
+    def __exit__(self, *args):
+        """Exit statement for with ... as ... handling."""
+        if self.isOpen:
+           self.close()
+
+
     def close(self):
         """Close a TREXIO File."""
-
         if self.isOpen:
             _close(self.pytrexio_s)
             self.isOpen = False
@@ -752,13 +761,11 @@ class File:
 
     def inquire(self):
         """Inquire whether a TREXIO file exists."""
-
         self.exists = _inquire(self.filename)
 
 
     def __del__(self):
-        """This is a TREXIO File destructor."""
-
+        """TREXIO File class destructor."""
         if self.isOpen:
             _close(self.pytrexio_s)
         elif self.isOpen is None: