Returning "ValidationError: 1 validation error for LLMChain prompt   value is not a valid dict (type=type_error.dict)" while trying to run the LLMChain
Labels: name: auto:bug, name: auto:question, name: area: models

### Issue with current documentation:

I have run the below code which will try to go through the csv file and return the answer

```
import pandas as pd
import json
from langchain.llms import OpenAI
from langchain.chains import LLMChain

openai_api_key = ''

# Read CSV file into a DataFrame
df = pd.read_csv('https://gist.githubusercontent.com/armgilles/194bcff35001e7eb53a2a8b441e8b2c6/raw/92200bc0a673d5ce2110aaad4544ed6c4010f687/pokemon.csv')

# del df['Due Date']
# del df['Closing Date']

# Create a dictionary of unique values per column
unique_values_per_column = {}
for column in df.select_dtypes(include=['object']).columns:
    # Convert ndarray to list
    unique_values_per_column[column] = df[column].unique().tolist()

# Convert the dictionary to JSON
json_data = json.dumps(unique_values_per_column, indent=4)

# Now you can use the json_data in your prompt
prompt_template = f'''If the dataset has the following columns: {json_data}

Understand user questions with different column names and convert them to a JSON format. Here's an example:

Example 1:
User Question: Top 2 zones by Housing Loan in the West and South in the year 2019 excluding small loans and with Discount > 5 and Term Deposit between 10k and 15k 

{{
    "start_date": "01-01-2019",
    "end_date": "31-12-2019",
    "time_stamp_col": "Month",
    "agg_columns": ["Housing Loan"],
    "trend": null,
    "to_start_date": null,
    "to_end_date": null,
    "growth": null,
    "variables_grpby": ["Zone"],
    "filters": {{"Zone": ["West", "South"]}},
    "not_in": {{"Loan Type": ["Small"]}},
    "num_filter": {{
        "gt": [
            ["Discount", 5],
            ["Term Deposit", 10000]
        ],
        "lt": [
            ["Term Deposit", 15000]
        ]
    }},
    "percent": false,
    "top": "2",
    "bottom": null
}}

Example 2:
User Question: What is the Highest Loan Amount and Loan Outstanding by RM Name James in January 2020

{{
    "start_date": "01-01-2020",
    "end_date": "31-01-2020",
    "time_stamp_col": "Due Date",
    "agg_columns": ["Loan Amount", "Loan Outstanding"],
    "trend": null,
    "to_start_date": null,
    "to_end_date": null,
    "growth": null,
    "variables_grpby": [],
    "filters": {{"RM Name": ["James"]}},
    "not_in": {{}},
    "num_filter": {{}},
    "percent": false,
    "top": "1",
    "bottom": null
}}

Example 3:
User Question: Which RM Name with respect to Region has the Highest Interest Outstanding and Principal Outstanding in the year 2019

{{
    "start_date": "01-01-2019",
    "end_date": "31-12-2019",
    "time_stamp_col": "Due Date",
    "agg_columns": ["Interest Outstanding", "Principal Outstanding"],
    "trend": null,
    "to_start_date": null,
    "to_end_date": null,
    "growth": null,
    "variables_grpby": ["RM Name", "Region"],
    "filters": {{}},
    "not_in": {{}},
    "num_filter": {{}},
    "percent": false,
    "top": "1",
    "bottom": null
}}

Example 4:
User Question: Which Branch in North Carolina with respect to Cibil Score Bucket has the Highest Cibil Score in 2019

{{
    "start_date": "01-01-2019",
    "end_date": "31-12-2019",
    "time_stamp_col": "Due Date",
    "agg_columns": ["Cibil Score", "DPD Bucket"],
    "trend": null,
    "to_start_date": null,
    "to_end_date": null,
    "growth": null,
    "variables_grpby": ["Branch"],
    "filters": {{"Region": ["North Carolina"]}},
    "not_in": {{}},
    "num_filter": {{}},
    "percent": false,
    "top": "1",
    "bottom": null
}}

Example 5:
User Question: With respect to Zone, Region, Branch, RM Name what is the Highest Loan Amount, Loan Tenure, Loan Outstanding, EMI Pending, Principal Outstanding

{{
    "start_date": null,
    "end_date": null,
    "time_stamp_col": null,
    "agg_columns": ["Loan Amount", "Loan Tenure", "Loan Outstanding", "EMI Pending", "Principal Outstanding"],
    "trend": null,
    "to_start_date": null,
    "to_end_date": null,
    "growth": null,
    "variables_grpby": ["Zone", "Region", "Branch", "RM Name"],
    "filters": {{}},
    "not_in": {{}},
    "num_filter": {{}},
    "percent": false,
    "top": "1",
    "bottom": null
}}

Example 6:
User Question: Top 2 zones by Housing Loan in the year 2019

{{
    "start_date": "01-01-2019",
    "end_date": "31-12-2019",
    "time_stamp_col": "Due Date",
    "agg_columns": ["Housing Loan"],
    "trend": null,
    "to_start_date": null,
    "to_end_date": null,
    "growth": null,
    "variables_grpby": ["Zone"],
    "filters": {{"Product": ["Home Loan"]}},
    "not_in": {{}},
    "num_filter": {{}},
    "percent": false,
    "top": "2",
    "bottom": null
}}


Our test dataset has the following columns: {json_data}

User Question (to be converted): {{user_question}}'''

# Use langchain to process the prompt
llm = OpenAI(api_key=openai_api_key, temperature=0.9)
chain = LLMChain(llm=llm, prompt=prompt_template)


user_question = "What is the Highest Loan Amount and Loan Outstanding by RM Name James in January 2020"
response = chain.run(user_question)
print(response)
```

Below is the error it's returning

```
WARNING! api_key is not default parameter.
                    api_key was transferred to model_kwargs.
                    Please confirm that api_key is what you intended.
---------------------------------------------------------------------------
ValidationError                           Traceback (most recent call last)
~\AppData\Local\Temp\ipykernel_22224\1265770286.py in <cell line: 169>()
    167 # Use langchain to process the prompt
    168 llm = OpenAI(api_key=openai_api_key, temperature=0.9)
--> 169 chain = LLMChain(llm=llm, prompt=prompt_template)
    170 
    171 

~\anaconda3\lib\site-packages\langchain\load\serializable.py in __init__(self, **kwargs)
     72 
     73     def __init__(self, **kwargs: Any) -> None:
---> 74         super().__init__(**kwargs)
     75         self._lc_kwargs = kwargs
     76 

~\anaconda3\lib\site-packages\pydantic\main.cp310-win_amd64.pyd in pydantic.main.BaseModel.__init__()

ValidationError: 1 validation error for LLMChain
prompt
  value is not a valid dict (type=type_error.dict)
```

Can anyone assist what exactly is the error?

### Idea or request for content:

_No response_