Merge pull request #3 from rcholic/modeling3

readme example

README.md

@@ -17,3 +17,36 @@ This is a Python client library for accessing the Charles Schwab stock and optio
 ## Installation
 
 To install the Charles Schwab API client, you can use pip:
+```
+pip install CSchwabPy
+```
+
+## Usage Example
+
+* Authentication & Get Access Token & Refresh Token
+
+```python
+
+# save these lines in a file named like cschwab.py
+from cschwabpy.SchwabAsyncClient import SchwabAsyncClient
+
+app_client_key = "---your-app-client-key-here-"
+app_secret = "app-secret"
+
+schwab_client = SchwabAsyncClient(app_client_id=app_client_key, app_secret=app_secret)
+schwab_client.get_tokens_manually()
+
+# run in your Terminal, follow the prompt to complete authentication:
+> python cschwab.py
+
+
+# now you should have access token & refresh token downloaded to your device
+
+#----------------
+# download SPX option chains
+from_date = 2024-07-01
+to_date = 2024-07-01
+ticker = '$SPX'
+asyncio.run(schwab_client.download_option_chain(ticker, from_date, to_date))
+
+```