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I've written a python code to check the unique values of the specified column names from a pandas dataframe.

What I have tried:

Main Code:

Checking the unique values & the frequency of their occurence

def uniq_fun(df, col_name):
    try:"Calculating the unique values and frequency for column '{col_name}'...")
        uniq_freq = df[col_name].value_counts(ascending=False)"Returning unique values and frequency for column '{col_name}' in a dictionary.")
        return uniq_freq.to_dict()
    except KeyError as e:
        logging.error(f"Column '{col_name}' not found in the dataframe: {e}")
    except Exception as e:
        logging.error(f"An unexpected error occurred while calculating the unique values and frequency for column '{col_name}': {e}")

def cleaning_and_analysis(filepath, operation=None, raw_data=None):

    file_extension = os.path.splitext(filepath)[1]
    if file_extension == '.csv':
        csv_dataframe = pd.read_csv(filepath, encoding='utf-8')
    result = {}
    if raw_data is not None and isinstance(raw_data, list):
        for i in raw_data:
             if operation=='uniqueValueFreq':   
                unique_value_freq_input= i
                result12= uniq_fun(csv_dataframe, unique_value_freq_input)
                if not result:
                     result[operation] = [(tuple(unique_value_freq_input), result12)]
                     result[operation].append((tuple(unique_value_freq_input), result12))

API Code:

from typing import Union
from typing import Optional
import uvicorn

from fastapi import FastAPI
from pydantic import BaseModel
from Data_Cleaning import cleaning_and_analysis
from typing import Any, Optional

app = FastAPI()

class Item(BaseModel):
    filepath: str
    operation: Optional[str] = None
    operand: Optional[Union[list, dict, str, tuple]] = None"/data_cleaning_route")
async def data_cleaning(item: Item):
    filepath = item.filepath
    operation_name = item.operation
    operands = item.operand
    cleaned_data = {} # initialize cleaned_data to an empty dictionary
    if operands is not None and len(operands) >= 1:
        for operand in operands:
            if isinstance(operand, dict): # check if i is a dictionary

              for operation_name,operand_values in operand.items():
                    cleaned_data.update(cleaning_and_analysis(filepath, operation=operation_name, raw_data=operand_values))
        return cleaned_data
        data_clean_var2 = cleaning_and_analysis(filepath=item.filepath, operation=item.operation)
        return data_clean_var2       

if __name__ == "__main__":, host="", port=8000)

Postman Payload:

"filepath": "C:/Downloads/shootings.csv",

"operand":[ {"uniqueValueFreq":[["flee"], ["race"]]}


TypeError: unhashable type: 'list'

What I've tried:

I converted the highlighted part from Main Code which was previously a dictionary, to a tuple. The same error continues. How do I fix this? The error is exactly at:

result[operation] = [(tuple(unique_value_freq_input), result12)]

Debugging Info:

API debugging


[['flee'], ['race']]

As we can see above, the API is able to read the postman inputs.

Main Code debugging:


{('White',): 2476, ('Black',): 1298, ('Hispanic',): 902, ('Asian',): 93, ('Native',): 78, ('Other',): 48}

This is the expected output. Not getting this when returning via API.

Note: Please let me know if any more inputs are needed to answer my query.
Updated 3-Apr-23 2:29am

1 solution

You need to look at the actual values that are being passed in to the following lines.
if not result:
     result[operation] = [(tuple(unique_value_freq_input), result12)]
     result[operation].append((tuple(unique_value_freq_input), result12))

You also need to provide the complete details of the error, including the output that shows which line of code caused the exception.
Share this answer
Apoorva 2022 3-Apr-23 9:13am    
Error: TypeError: unhashable type: 'list' is in this line--->
result[operation] = [(tuple(unique_value_freq_input), result12)].

Output: [(('flee',), {('Not fleeing',): 3073, ('Car',): 820, ('Foot',): 642, ('Other',): 360}), (('race',), {('White',): 2476, ('Black',): 1298, ('Hispanic',): 902, ('Asian',): 93, ('Native',): 78, ('Other',): 48})]

I mentioned these in the question as well, but it was a bit scattered. So compiled them here. Hope I've provided all the necessary details.
Richard MacCutchan 3-Apr-23 9:39am    
What are the actual values of operation, unique_value_freq_input and result12? One of those is causing the problem, but we need to see them.
Apoorva 2022 3-Apr-23 9:47am    
Operation= "uniqueValueFreq" (a name given to the function under consideration that triggers the output. There are many different modules in my code & they have been assigned different names which are contained in a string)

unique_value_freq_input= "flee", "race" (columns from the dataframe)

result12= Output: [(('flee',), {('Not fleeing',): 3073, ('Car',): 820, ('Foot',): 642, ('Other',): 360}), (('race',), {('White',): 2476, ('Black',): 1298, ('Hispanic',): 902, ('Asian',): 93, ('Native',): 78, ('Other',): 48})]

The output of the code lists the unique values under the columns "flee" & "race" & the frequency of their occurence in the dataframe.
Richard MacCutchan 3-Apr-23 10:31am    
OK, I just pasted those values and the associated code into my Python script and it works fine:
    result = {}
    operation= "uniqueValueFreq"
    unique_value_freq_input= ["flee", "race"]
    result12= [(('flee',), {('Not fleeing',): 3073, ('Car',): 820, ('Foot',): 642, ('Other',): 360}), (('race',), {('White',): 2476, ('Black',): 1298, ('Hispanic',): 902, ('Asian',): 93, ('Native',): 78, ('Other',): 48})]
    result[operation] = [(tuple(unique_value_freq_input), result12)]
    result[operation].append((tuple(unique_value_freq_input), result12))    

So there must be something else going on in your code.
Apoorva 2022 3-Apr-23 10:35am    
Yes, the issue seems to be with the API code. Not able to figure that out. I think the issue is with the looping within API, because the code works for the modules whose each input contains multiple values, example- "operand": [{"fillWithDesiredValue": [["sod",999], ["rbc","great"]]}]. In case of single input for an operation like the one in question, "operand":[ {"uniqueValueFreq":[["flee"],["race"]]}, where each input requires only a single value, the error in the question arises.

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