How to Drop rows in DataFrame by conditions on column values in Python ?
In this article we will discuss how we can delete rows in a dataframe by certain conditions on column values.
DataFrame provides a member function drop() which is used to drop specified labels from rows or columns in dataframe.
DataFrame.drop(self, labels=None, axis=0, index=None, columns=None, level=None, inplace=False, errors=’raise’)
Let’s try with an example:
#Program :
import pandas as pd
#list of tuples
game = [('riya',37,'delhi','cat','rose'),
('anjali',28,'agra','dog','lily'),
('tia',42,'jaipur','elephant','lotus'),
('kapil',51,'patna','cow','tulip'),
('raj',30,'banglore','lion','orchid')]
#Create a dataframe object
df = pd.DataFrame(game, columns=['Name','Age','Place','Animal','Flower'], index=['a','b','c','d','e'])
print(df)
Output:    Name Age    Place   Animal Flower a   riya  37    delhi      cat   rose b anjali  28     agra      dog   lily c    tia  42   jaipur elephant  lotus d  kapil  51    patna      cow  tulip e    raj  30 banglore     lion orchid
Delete rows based on condition on a column
Let’s try with an example by deleting a row:
deleteRow = df[df['Place'] == 'patna'].index df.drop(deleteRow, inplace=True) print(df)
Output: Name Age    Place   Animal Flower a   riya  37    delhi      cat   rose b anjali  28     agra      dog   lily c    tia  42   jaipur elephant  lotus e    raj  30 banglore     lion orchid
Here, we give the condition i.e
df[‘Place’] == ‘patna’
Internally if we will see it is giving series object with True and False.
a  False b  False c  False d  True e  False
Name: Place, dtype: bool
Delete rows based on multiple conditions on a column :
Let’s try with multiple conditions
deleteRow = df[(df['Age'] >= 30) & (df['Age'] <= 40)].index df.drop(deleteRow, inplace=True) print(df)
Output:    Name Age    Place   Animal  Flower b anjali  28     agra      dog   lily c    tia  42   jaipur elephant  lotus
Here, we join two conditions i.e df[‘Age’]>=30 and df[‘Age’]<=40 by putting ’&’ between two conditions.
Want to expert in the python programming language? Exploring Python Data Analysis using Pandas tutorial changes your knowledge from basic to advance level in python concepts.
Read more Articles on Python Data Analysis Using Padas – Remove Contents from a Dataframe