Deleting rows based of a condition Python Pandas

Question

I want to delete rows when a condition when is met: I need to drop any value that is less than zero in specific column.

For instance,I import a csv file:

import pandas as pd
df=pd.read_csv('Surface_Time_PS.csv') 
df.drop_duplicates(subset='DEPTH',keep='first',inplace=True) #DROP ANY DUPLICATION IN DEPTH 

df['Difference1']=df['DEPTH(ft)'].diff()
df['Difference1']

for x in "df.Difference1":
    if [df['Difference1'].diff() < 0]:
        df.drop(df[df['Difference1'].diff() < 0].index, inplace=False)           #FUNCTION WHERE IS THE DIFF IN DEPTH IS MUST BE POSITIVE OTHER WISE DROP THE row
    else:
        df

after running this code, I get rid of most of the row with negative value in Difference1 dropped. But still I have few negative value.

I want the code to repeat the process until the column has only positive values

You can use boolean indexing, df[df.Difference1 >=0] or df[~(df.Difference1 < 0)] — Vaishali, Apr 15 '19 at 16:47

score 2 · Accepted Answer · answered Apr 15 '19 at 16:46

2

Remove for loop statement and put this line below:

df.drop(df[df['Difference1'] < 0].index, inplace=True)

answered Apr 15 '19 at 16:46

Kafels

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Deleting rows based of a condition Python Pandas

1 Answers1