Click here to Skip to main content
15,845,565 members
Please Sign up or sign in to vote.
0.00/5 (No votes)
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 3:29am

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.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

CodeProject, 20 Bay Street, 11th Floor Toronto, Ontario, Canada M5J 2N8 +1 (416) 849-8900