How to Drop Duplicates In A Pandas DataFrame?

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To drop duplicates in a pandas DataFrame, you can use the drop_duplicates() method. This method will remove rows that have duplicate values in all columns. By default, it keeps the first occurrence of the duplicates and removes the rest. You can also specify the subset parameter to only consider certain columns when determining duplicates. Additionally, you can use the keep parameter to specify whether to keep the first occurrence, last occurrence, or none of the duplicates. After dropping duplicates, the index of the DataFrame will be reset to maintain a contiguous index.

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How to drop duplicates in a pandas DataFrame while keeping the original order of rows?

You can drop duplicates in a pandas DataFrame while keeping the original order of rows by using the drop_duplicates() method with the parameter keep='first'. This will remove duplicate rows and keep the first occurrence of each unique row in the original order. Here is an example:

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import pandas as pd

# Create a sample DataFrame
df = pd.DataFrame({'A': [1, 2, 2, 3, 4, 3],
                   'B': ['a', 'b', 'b', 'c', 'd', 'c']})

# Drop duplicates while keeping the original order of rows
df_no_duplicates = df.drop_duplicates(keep='first')

print(df_no_duplicates)


This will output:

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4
5
   A  B
0  1  a
1  2  b
3  3  c
4  4  d



How to drop duplicates in a pandas DataFrame and keep the original order of rows?

You can drop duplicates in a pandas DataFrame while keeping the original order of rows by using the drop_duplicates() method with the keep='first' parameter.


Here is an example of how you can drop duplicates in a pandas DataFrame while preserving the original order of rows:

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import pandas as pd

# Create a sample DataFrame
data = {'A': [1, 2, 2, 3, 4, 4, 5],
        'B': ['a', 'b', 'b', 'c', 'd', 'd', 'e']}
df = pd.DataFrame(data)

# Drop duplicates and keep the first occurrence
df_no_duplicates = df.drop_duplicates(keep='first')

print(df_no_duplicates)


This code will remove the duplicates from the DataFrame df while keeping the first occurrence of each duplicate row. The resulting DataFrame df_no_duplicates will have the original order of rows preserved.


What is the syntax for dropping duplicates in a pandas DataFrame?

To drop duplicates in a pandas DataFrame, you can use the drop_duplicates() method. The syntax is as follows:

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df.drop_duplicates(subset=None, keep='first', inplace=False)


  • subset: Specifies columns to consider for identifying duplicates. If not specified, all columns are considered.
  • keep: Specifies which duplicates to keep. Options are 'first', 'last', or False. Default is 'first'.
  • inplace: Specifies whether to drop duplicates in place or return a new DataFrame. Default is False.


What is the default behavior of the drop_duplicates() function in pandas?

By default, the drop_duplicates() function in pandas keeps the first occurrence of a duplicated row and removes all subsequent duplicated rows. This means that only the first occurrence of each duplicated row is retained in the DataFrame, and all subsequent duplicated rows are dropped.


How to drop duplicates in a pandas DataFrame based on a condition or criteria?

You can drop duplicates in a pandas DataFrame based on a condition or criteria using the drop_duplicates() method with the subset parameter. This parameter allows you to specify the columns that should be used to determine duplicates.


Here's an example of how you can drop duplicates in a pandas DataFrame based on a specific column value:

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import pandas as pd

# Create a sample DataFrame
data = {'col1': [1, 2, 3, 3, 4, 5],
        'col2': ['A', 'B', 'C', 'D', 'E', 'F']}
df = pd.DataFrame(data)

# Drop duplicates based on the 'col1' column
df = df.drop_duplicates(subset='col1', keep='first')

print(df)


In this example, the drop_duplicates() method is used to remove rows that have duplicate values in the 'col1' column. The keep='first' parameter specifies that the first occurrence of the duplicate value should be kept, and subsequent duplicates should be removed.


You can also specify multiple columns in the subset parameter to drop duplicates based on multiple criteria. For example:

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# Drop duplicates based on multiple columns
df = df.drop_duplicates(subset=['col1', 'col2'], keep='first')


This code will drop rows that have duplicate values in both the 'col1' and 'col2' columns.

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