Why can't I drop any columns in dataframe?

Question

I don't know why unnamed: 0 got there when I reversed the index and for the life of me, I can't drop or del it. It will NOT go away. No matter what I do, by index or by any possible string variation from 'Unnamed: 0' to just '0'. I've tried setting it by columns= or by .drop(df.columns, I've tried everything already in my code such as drop=True. Then I tried dropping other columns and that wouldn't work.

import pandas as pd

# set csv file as constant
TRADER_READER = pd.read_csv('TastyTrades.csv')


# change date format, make date into timestamp object, set date as index, write changes to csv file
def clean_date():
    # TRADER_READER['Date'] = TRADER_READER['Date'].replace({'T': ' ', '-0500': '', '-0400': ''}, regex=True)
    # TRADER_READER['Date'] = pd.to_datetime(TRADER_READER['Date'], format="%Y-%m-%d %H:%M:%S")
    TRADER_READER.set_index('Date', inplace=True, drop=True)
    # TRADER_READER.iloc[::-1].reset_index(drop=True)
    print(TRADER_READER)
    # TRADER_READER.to_csv('TastyTrades.csv')


clean_date()

                     Unnamed: 0             Type  ... Strike Price Call or Put
Date                                              ...                         
2020-04-01 11:00:05           0            Trade  ...         21.0         PUT
2020-04-01 11:00:05           1            Trade  ...          NaN         NaN
2020-03-31 17:00:00           2  Receive Deliver  ...         22.0         PUT
2020-03-31 17:00:00           3  Receive Deliver  ...          NaN         NaN
2020-03-27 16:15:00           4  Receive Deliver  ...          7.5         PUT
...                         ...              ...  ...          ...         ...
2019-12-12 10:10:22         617            Trade  ...         11.0         PUT
2019-12-12 10:10:21         618            Trade  ...         45.0        CALL
2019-12-12 10:10:21         619            Trade  ...         32.5         PUT
2019-12-12 09:45:42         620            Trade  ...         18.0        CALL
2019-12-12 09:45:42         621            Trade  ...         13.0         PUT

[622 rows x 16 columns]

Process finished with exit code 0

Can you please show the head of the dataframe after you read it from the CSV? — jcaliz, Apr 12 '20 at 00:46
Did you try `TRADER_READER = TRADER_READER.drop('Unnamed: 0', axis=1)`? — pandichef, Apr 12 '20 at 00:48
I guess I must've missed a character because it's gone. I originally did what you suggested. Thank you. — Luck Box, Apr 12 '20 at 00:54

score 0 · Answer 1 · answered Apr 12 '20 at 00:49

0

I think the problem is from the CSV that includes a non-named column, to fix it, read the csv specifying to use the first column as index, and then set the Date index.

TRADER_READER = pd.read_csv('TastyTrades.csv', index_col=0)
TRADER_READER.set_index('Date', inplace=True, drop=True)

answered Apr 12 '20 at 00:49

jcaliz

3,891
2
9
13

Date column got deleted and now I am re-downloading the file. – Luck Box Apr 12 '20 at 01:06

Why can't I drop any columns in dataframe?

1 Answers1