Added OFModel class to write fields

olaflow/processing/olaflow.py

@@ -0,0 +1,21 @@
+import re
+
+
+class OFModel:
+    def __init__(self, root):
+        self._root = root
+
+    def write_field(self, field, values):
+        with open(self._root.joinpath("0", field), "r") as aw_file:
+            aw_raw = aw_file.read()
+
+        with open(self._root.joinpath("0", field), "w") as aw_file:
+            aw_file.write(
+                re.sub(
+                    r"(?<=\(\n).*?(?=\n\))",
+                    "\n".join(values.astype(str)),
+                    aw_raw,
+                    count=1,
+                    flags=re.S,
+                )
+            )