better error handling/reporting

2 files changed, 18 insertions, 2 deletions

diff --git a/README.md b/README.md
index 5d6f933..1f15e17 100644
--- a/README.md
+++ b/README.md
@@ -49,3 +49,13 @@ import requests
 r = requests.post("http://localhost:8080", data={"url": "http://example.com/image.jpg"})
 nsfw_prob = float(r.text)
 ```
+
+# HTTP Errors
+
+## 415 Unsupported Media Type: Invalid image
+
+The requested `url` is not a valid image.
+
+## 400 Bad Request: Missing `url` POST parameter
+
+You need to specify `url` as a POST parameter.
diff --git a/api.py b/api.py
index de3c888..39a4937 100644
--- a/api.py
+++ b/api.py
@@ -5,6 +5,7 @@ import async_timeout
 import numpy as np
 import uvloop
 from aiohttp import web
+from aiohttp.web import HTTPBadRequest, HTTPUnsupportedMediaType
 
 from classify_nsfw import caffe_preprocess_and_compute, load_model
 
@@ -30,8 +31,13 @@ class API(web.View):
             nsfw_prob = classify(image)
             text = nsfw_prob.astype(str)
             return web.Response(text=text)
-        except:
-            raise web.HTTPBadRequest()
+        except KeyError:
+            return HTTPBadRequest(text="Missing `url` POST parameter")
+        except OSError as e:
+            if "cannot identify" in str(e):
+                raise HTTPUnsupportedMediaType(text="Invalid image")
+            else:
+                raise e
 
 
 asyncio.set_event_loop_policy(uvloop.EventLoopPolicy())