serpapi.HTTPError missing the essential status code and error (#22)

* Populate HTTPError with status code and error

* Add error handling example to README

* Handle edge cases in HTTPError

Author: tanys123

README.md

@@ -50,6 +50,29 @@ Let's print the title of the first result, but in a more Pythonic way:
 
 The [SerpApi.com API Documentation](https://serpapi.com/search-api) contains a list of all the possible parameters that can be passed to the API.
 
+### Error handling
+
+Unsuccessful requests raise `serpapi.HTTPError` exception. The returned status code will reflect the sort of error that occurred, please refer to [Status and Error Codes Documentation](https://serpapi.com/api-status-and-error-codes) for more details.
+
+```python
+import serpapi
+
+client = serpapi.Client(api_key=os.getenv("API_KEY"))
+
+try:
+    results = client.search({
+        'engine': 'google',
+        'q': 'coffee',
+    })
+except serpapi.HTTPError as e:
+    if e.status_code == 401: # Invalid API key
+        print(e.error) # "Invalid API key. Your API key should be here: https://serpapi.com/manage-api-key"
+    elif e.status_code == 400: # Missing required parameter
+        pass
+    elif e.status_code == 429: # Exceeds the hourly throughput limit OR account run out of searches
+        pass
+```
+
 ## Documentation
 
 Documentation is [available on Read the Docs](https://serpapi-python.readthedocs.io/en/latest/).
@@ -339,7 +362,6 @@ results = client.search({
 ```
 - API Documentation: [serpapi.com/images-results](https://serpapi.com/images-results)
 
-
 ## License
 
 MIT License.

serpapi/exceptions.py

@@ -22,7 +22,21 @@ class SearchIDNotProvided(ValueError, SerpApiError):
 class HTTPError(requests.exceptions.HTTPError, SerpApiError):
     """HTTP Error."""
 
-    pass
+    def __init__(self, original_exception):
+        if (isinstance(original_exception, requests.exceptions.HTTPError)):
+            http_error_exception: requests.exceptions.HTTPError = original_exception
+
+            self.status_code = http_error_exception.response.status_code
+            try:
+                self.error = http_error_exception.response.json().get("error", None)
+            except requests.exceptions.JSONDecodeError:
+                self.error = None
+        else:
+            self.status_code = -1
+            self.error = None
+                
+        super().__init__(*original_exception.args, response=getattr(original_exception, 'response', None), request=getattr(original_exception, 'request', None))
+
 
 
 class HTTPConnectionError(HTTPError, requests.exceptions.ConnectionError, SerpApiError):

tests/test_exceptions.py

@@ -0,0 +1,17 @@
+from unittest.mock import Mock
+import requests
+import serpapi
+
+
+def test_http_error():
+    """Ensure that an HTTPError has the correct status code and error."""
+    mock_response = Mock()
+    mock_response.status_code = 401
+    mock_response.json.return_value = { "error": "Invalid API key" }
+    
+    requests_error = requests.exceptions.HTTPError(response=mock_response, request=Mock())
+    http_error = serpapi.HTTPError(requests_error)
+        
+    assert http_error.status_code == 401
+    assert http_error.error == "Invalid API key"
+    assert http_error.response == mock_response

tests/test_integration.py

@@ -26,8 +26,10 @@ def test_account_without_credentials():
 
 def test_account_with_bad_credentials(invalid_key_client):
     """Ensure that an HTTPError is raised when account is accessed with invalid API Credentials."""
-    with pytest.raises(serpapi.HTTPError):
+    with pytest.raises(serpapi.HTTPError) as exc_info:
         invalid_key_client.account()
+        
+    assert exc_info.value.response.status_code == 401
 
 
 def test_account_with_credentials(client):
@@ -38,6 +40,14 @@ def test_account_with_credentials(client):
     assert isinstance(account, dict)
 
 
+def test_search_with_missing_params(client):
+    with pytest.raises(serpapi.HTTPError) as exc_info:
+        client.search({ "q": "" })
+        
+    assert exc_info.value.status_code == 400
+    assert "Missing query `q` parameter" in exc_info.value.error
+
+
 def test_coffee_search(coffee_search):
     assert isinstance(coffee_search, serpapi.SerpResults)
     assert hasattr(coffee_search, "__getitem__")