drop_duplicates() to delete duplicate values from a series in Pandas

Series.drop_duplicates(keep)

keep Optional ,
'first' default, all duplicates are marked True except first one
'last', all duplicates are marked True except last one
'False',all duplicates are marked True

Series : Deletes duplicate values.
DataFrame :Deletes duplicate rows.
dataframe.drop_duplicates()

Using Series

In our series below, we have one element as duplicate value ( 'Two' )

import pandas as pd
my_data=pd.Series(['One','Two','Three','Two','Four'])
df=my_data.drop_duplicates()
print(df)

Output ( default value of keep is first , keep='first')

0      One
1      Two
2    Three
4     Four
dtype: object

With keep='last', duplicate values are deleted except last one

df=my_data.drop_duplicates(keep='last')
print(df)

0      One
2    Three
3      Two
4     Four
dtype: object

with keep=False , all duplicate values are deleted

df=my_data.drop_duplicates(keep=False)
print(df)

Output

0      One
2    Three
4     Four
dtype: object

inplace=True

By default inplace=False, so our main dataframe my_data is not altered when we use drop_duplicates(). So in above codes we have used another DataFrame df to store the output of drop_duplicates(). By using inplace=True we can modify our main DataFrame my_data

import pandas as pd
my_data=pd.Series(['One','Two','Three','Two','Four'])
my_data.drop_duplicates(keep='last',inplace=True)
print(my_data)

Output

0      One
2    Three
3      Two
4     Four
dtype: object

Data Cleaning

Pandas dataframe.duplicated() Series.duplicated() dataframe.drop_duplicates()

Numpy arrays Python & MySQL Python- Tutorials

Subhendu Mohapatra

Author & Instructor at plus2net

I write and maintain practical tutorials on Python, PHP, SQL, JavaScript, HTML, jQuery, and web development at plus2net. The tutorials focus on clear explanations, working examples, and code that readers can test and adapt while learning.

About the author Watch on YouTube

Connect:

Subscribe to our YouTube Channel here

drop_duplicates() : deleting duplicate values

Using Series

inplace=True

Subhendu Mohapatra