Add a method to map over the content of a corpus

GEODE/Store/Corpus.py

@@ -67,6 +67,25 @@ class TSVIndexed(Corpus):
             if where is None or where(*row):
                 yield projector(*row)
 
+    """
+    A map over the content of a corpus with filter-capability
+
+    Positional arguments
+    :param function f: the function to apply on each text of the corpus. It must
+    accept a `row` as input (i.e. a `dict` containing the primary key for the
+    text and its content associated to the `column_name` attribute of the
+    corpus on which this method is called) and returning the transformed content
+    (or `None` if the text shouldn't be kept)
+
+    :return: a generator over the transformed corpus, skipping elements for
+    which `f` returns `None`)
+    """
+    def map_content(self, f):
+        for row in self.get_all():
+            newContent = f(row)
+            if newContent is not None:
+                yield {**row, self.column_name: newContent}
+
 class SelfContained(TSVIndexed):
     """
     A class to handle the dataset TSV normalised path used in the project and loading the