refactor: move NLP processing out of server file

server/nlp_processor.py

@@ -0,0 +1,28 @@
+import torch
+import pandas as pd
+
+from transformers import pipeline
+
+emotion_classifier = pipeline(
+    "text-classification",
+    model="j-hartmann/emotion-english-distilroberta-base",
+    top_k=None,
+    truncation=True,
+    device=0 if torch.cuda.is_available() else -1
+)
+
+def add_emotion_cols(df: pd.Dataframe, content_col: str) -> None:
+    texts = df[content_col].astype(str).str.slice(0, 512).tolist()
+
+    results = emotion_classifier(
+        texts,
+        batch_size=64
+    )
+
+    labels = [r["label"] for r in results[0]]
+
+    for label in labels:
+        df[f"emotion_{label}"] = [
+            next(item["score"] for item in row if item["label"] == label)
+            for row in results
+        ]