Update langchain usage in tutorial (#1116)

* docs: update langchain usage

* Update instructions to match

---------

Co-authored-by: Debbie Matthews <[email protected]>

content/develop/tutorials/llms/llm-quickstart.md

@@ -36,7 +36,7 @@ Bonus: Deploy the app on Streamlit Community Cloud!
 In your IDE (integrated coding environment), open the terminal and install the following three Python libraries:
 
 ```python
-pip install streamlit openai langchain
+pip install streamlit openai langchain langchain-community langchain-openai
 ```
 
 Create a `requirements.txt` file located in the root of your working directory and save these dependencies. This is necessary for deploying the app to the Streamlit Community Cloud later.
@@ -53,23 +53,29 @@ The app is only 18 lines of code:
 
 ```python
 import streamlit as st
-from langchain.llms import OpenAI
+from langchain_openai.chat_models import ChatOpenAI
 
-st.title('🦜🔗 Quickstart App')
+st.title("🦜🔗 Quickstart App")
+
+openai_api_key = st.sidebar.text_input("OpenAI API Key", type="password")
 
-openai_api_key = st.sidebar.text_input('OpenAI API Key', type='password')
 
 def generate_response(input_text):
-    llm = OpenAI(temperature=0.7, openai_api_key=openai_api_key)
-    st.info(llm(input_text))
-
-with st.form('my_form'):
-    text = st.text_area('Enter text:', 'What are the three key pieces of advice for learning how to code?')
-    submitted = st.form_submit_button('Submit')
-    if not openai_api_key.startswith('sk-'):
-        st.warning('Please enter your OpenAI API key!', icon='⚠')
-    if submitted and openai_api_key.startswith('sk-'):
+    model = ChatOpenAI(temperature=0.7, api_key=openai_api_key)
+    st.info(model.invoke(input_text))
+
+
+with st.form("my_form"):
+    text = st.text_area(
+        "Enter text:",
+        "What are the three key pieces of advice for learning how to code?",
+    )
+    submitted = st.form_submit_button("Submit")
+    if not openai_api_key.startswith("sk-"):
+        st.warning("Please enter your OpenAI API key!", icon="⚠")
+    if submitted and openai_api_key.startswith("sk-"):
         generate_response(text)
+
 ```
 
 To start, create a new Python file and save it as `streamlit_app.py` in the root of your working directory.
@@ -78,38 +84,41 @@ To start, create a new Python file and save it as `streamlit_app.py` in the roo
 
    ```python
    import streamlit as st
-   from langchain.llms import OpenAI
+   from langchain_openai.chat_models import ChatOpenAI
    ```
 
 2. Create the app's title using `st.title`.
 
    ```python
-   st.title('🦜🔗 Quickstart App')
+   st.title("🦜🔗 Quickstart App")
    ```
 
 3. Add a text input box for the user to enter their OpenAI API key.
 
    ```python
-   openai_api_key = st.sidebar.text_input('OpenAI API Key', type='password')
+   openai_api_key = st.sidebar.text_input("OpenAI API Key", type="password")
    ```
 
 4. Define a function to authenticate to OpenAI API with the user's key, send a prompt, and get an AI-generated response. This function accepts the user's prompt as an argument and displays the AI-generated response in a blue box using `st.info`.
 
    ```python
    def generate_response(input_text):
-       llm = OpenAI(temperature=0.7, openai_api_key=openai_api_key)
-       st.info(llm(input_text))
+   model = ChatOpenAI(temperature=0.7, api_key=openai_api_key)
+       st.info(model.invoke(input_text))
    ```
 
 5. Finally, use `st.form()` to create a text box (`st.text_area()`) for user input. When the user clicks `Submit`, the `generate-response()` function is called with the user's input as an argument.
 
    ```python
-   with st.form('my_form'):
-       text = st.text_area('Enter text:', 'What are the three key pieces of advice for learning how to code?')
-       submitted = st.form_submit_button('Submit')
-       if not openai_api_key.startswith('sk-'):
-           st.warning('Please enter your OpenAI API key!', icon='⚠')
-       if submitted and openai_api_key.startswith('sk-'):
+   with st.form("my_form"):
+       text = st.text_area(
+           "Enter text:",
+           "What are the three key pieces of advice for learning how to code?",
+       )
+       submitted = st.form_submit_button("Submit")
+       if not openai_api_key.startswith("sk-"):
+           st.warning("Please enter your OpenAI API key!", icon="⚠")
+       if submitted and openai_api_key.startswith("sk-"):
            generate_response(text)
    ```
 

python/tutorial-source/llm-18-lines-of-code/streamlit_app.py

@@ -1,18 +1,23 @@
 import streamlit as st
-from langchain.llms import OpenAI
+from langchain_openai.chat_models import ChatOpenAI
 
-st.title('🦜🔗 Quickstart App')
+st.title("🦜🔗 Quickstart App")
+
+openai_api_key = st.sidebar.text_input("OpenAI API Key", type="password")
 
-openai_api_key = st.sidebar.text_input('OpenAI API Key', type='password')
 
 def generate_response(input_text):
-    llm = OpenAI(temperature=0.7, openai_api_key=openai_api_key)
-    st.info(llm(input_text))
+    model = ChatOpenAI(temperature=0.7, api_key=openai_api_key)
+    st.info(model.invoke(input_text))
+
 
-with st.form('my_form'):
-    text = st.text_area('Enter text:', 'What are the three key pieces of advice for learning how to code?')
-    submitted = st.form_submit_button('Submit')
-    if not openai_api_key.startswith('sk-'):
-        st.warning('Please enter your OpenAI API key!', icon='⚠')
-    if submitted and openai_api_key.startswith('sk-'):
+with st.form("my_form"):
+    text = st.text_area(
+        "Enter text:",
+        "What are the three key pieces of advice for learning how to code?",
+    )
+    submitted = st.form_submit_button("Submit")
+    if not openai_api_key.startswith("sk-"):
+        st.warning("Please enter your OpenAI API key!", icon="⚠")
+    if submitted and openai_api_key.startswith("sk-"):
         generate_response(text)