Redirect if text query param missing (#20)

* Redirect if text query param missing

* Update __init__.py

Co-authored-by: Aaron Wislang <asw101@users.noreply.github.com>

4-azure-functions-python-vscode/sentiment/__init__.py

@@ -5,7 +5,9 @@
 def main(req: func.HttpRequest) -> func.HttpResponse:
     analyzer = SentimentIntensityAnalyzer()
     text = req.params.get("text")
+    if text is None:
+        return func.HttpResponse(status_code=302, headers={"Location":req.url+"?text=I+Love+PyCon"})
     scores = analyzer.polarity_scores(text)
     sentiment = "positive" if scores["compound"] > 0 else "negative"
     return func.HttpResponse(sentiment)
-
+