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pythonpandasdataframerow

Loop the removal of pandas dataframe rows


I want to loop the deletion of rows until I reach the row with the time value of 04:30:00, and then stop the deletion process. How do I do that?

Here is an example of my data:

ticker  date    time    vol     vwap    open    high    low close
0   AACG    2022-01-06  04:07:00    242 2.0400  2.04    2.04    2.04    2.04
1   AACG    2022-01-06  04:08:00    427 2.0858  2.06    2.10    2.06    2.10
2   AACG    2022-01-06  04:09:00    906 2.1098  2.10    2.11    2.10    2.11
3   AACG    2022-01-06  04:16:00    186 2.1108  2.12    2.12    2.10    2.10
4   AACG    2022-01-06  04:30:00    237 2.0584  2.06    2.06    2.06    2.06
5   AACG    2022-01-06  04:31:00    700 2.1098  2.10    2.11    2.10    2.11

I tried this but it doesn't show that anything has changed:

row = 0
while df['time'].values[row] == datetime.time(4, 30) == False:
    print(df['time'].values[row])
    df.drop(row, axis=0, inplace=True)
    row = row + 1

Here is the df.info():

<class 'pandas.core.frame.DataFrame'>
RangeIndex: 10 entries, 0 to 9
Data columns (total 12 columns):
ticker    10 non-null object
date      10 non-null object
time      10 non-null object
vol       10 non-null int64
vwap      10 non-null float64
open      10 non-null float64
high      10 non-null float64
low       10 non-null float64
close     10 non-null float64
lbh       10 non-null int64
lah       10 non-null int64
trades    10 non-null int64
dtypes: float64(5), int64(4), object(3)
memory usage: 1.1+ KB

UPDATE: Thanks again for your help everyone.

df[df['time'] >= datetime.time(4, 30)] helped me remove unnecessary rows.


Solution

  • You don't need a loop here if you convert your time column to a TimedeltaIndex:

    out = df[~pd.to_timedelta(df['time']).lt('04:30:00')]
    print(out)
    
    # Output
      ticker        date      time         vol  vwap  open  high  low close
    4   AACG  2022-01-06  04:30:00  237 2.0584  2.06  2.06  2.06       2.06
    5   AACG  2022-01-06  04:31:00  700 2.1098  2.10  2.11  2.10       2.11
    

    Does it work?

    from datetime import time
    
    out = df[df['time'] >= time(4, 30)]
    print(out)
    
    # Output:
      ticker        date      time         vol  vwap  open  high  low close
    4   AACG  2022-01-06  04:30:00  237 2.0584  2.06  2.06  2.06       2.06
    5   AACG  2022-01-06  04:31:00  700 2.1098  2.10  2.11  2.10       2.11
    
    # Info
    print(df['time'].iloc[0])
    # datetime.time(4, 7)