Pandas – Drop First Three Rows From DataFrame

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  • Post category:Pandas
  • Post last modified:May 15, 2024
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To drop the first three rows from a Pandas DataFrame, you can use the drop() method with the index parameter set to a list containing the row indices you want to remove.

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In this article, I will explain how to drop the first three rows from DataFrame by using either drop(), iloc[], or tail() functions.

Key Points –

  • Pandas provides the drop() method to remove rows or columns from a DataFrame.
  • Slicing with .index[:3] selects the first three-row indices for removal.
  • The drop() method can be applied directly to the DataFrame object.
  • Using inplace=True within drop() modifies the original DataFrame in place without creating a new one.
  • The drop() method provides flexibility in specifying the rows or columns to be removed based on index labels or positions, enhancing the data manipulation capabilities of Pandas DataFrames.

Quick Examples of Drop First Three Rows

Below are some quick examples of how to drop the first two/three rows from DataFrame.


# Quick examples of drop first three rows 

# Use DataFrame.iloc[]
# To drop first three rows 
df2 = df.iloc[3:]

# Use DataFrame.iloc[]
n = 3
df2 = df.iloc[n:]

# Use DataFrame.drop() function 
# To delete first three rows
df.drop(df.head(3).index, inplace=True)

# Use DataFrame.drop() function
df.drop(df.index[:3], inplace=True)

# Use DataFrame.tail() method 
# To drop first three rows
df2 = df.tail(-3)

To run some examples of dropping the first three rows from Pandas DataFrame, let’s create Pandas DataFrame using data from a dictionary.


# Create DataFrame
import pandas as pd
technologies = {
    'Courses':["Spark","PySpark","Python","pandas","Hadoop"],
    'Fee' :[20000,25000,22000,24000,30000],
    'Duration':['30day','40days','35days','60days','55days'],
    'Discount':[1000,2300,2500,2000,3000]
              }
index_labels=['r1','r2','r3','r4','r5']
df = pd.DataFrame(technologies,index=index_labels)
print("Original DataFrame\n",df)

Yields below output.

Pandas drop first three Rows

Use DataFrame.iloc[] to Drop First Three Rows

By using DataFrame.iloc[] you can drop the rows from DataFrame and use 3: it to drop the first three rows. For instance, used DataFrame.iloc[3:] to filter and select all rows except the first three, effectively removing those initial rows from the DataFrame, and then reassigning the resulting DataFrame back to the original variable.


# Use DataFrame.iloc[] to drop first three rows 
df2 = df.iloc[3:]
print(df2) 

# Use DataFrame.iloc[]
n = 3
df2 = df.iloc[n:]
print(df2)

# Output:
#    Courses    Fee Duration  Discount
# r4  pandas  24000   60days      2000
# r5  Hadoop  30000   55days      3000

Use DataFrame.drop() to Delete First Three Rows

Alternatively, you can also utilize the DataFrame.drop() method to eliminate the first three rows. Specify the first index using the index parameter and set inplace=True to apply the change directly to the existing DataFrame. For instance, df.drop(df.head(3).index, inplace=True) method.


# Use DataFrame.drop() function 
# To delete first three rows
df.drop(df.head(3).index, inplace=True)
print(df) 

# Use DataFrame.drop() function
df.drop(df.index[:3], inplace=True)
print(df)

# Output:
#    Courses    Fee Duration  Discount
# r4  pandas  24000   60days      2000
# r5  Hadoop  30000   55days      3000

Use DataFrame.tail() Method to Drop First Three Rows

The DataFrame.tail() method is typically used to retrieve the last n rows of a DataFrame. However, we can manipulate it slightly to drop the first three rows by combining it with the negative indexing feature.


# Use DataFrame.tail() method to drop first three rows
df2 = df.tail(-3)
print(df2) 

# Output:
#    Courses    Fee Duration  Discount
# r4  pandas  24000   60days      2000
# r5  Hadoop  30000   55days      3000

Complete Example for Drop First Three Rows


import pandas as pd
technologies = {
    'Courses':["Spark","PySpark","Python","pandas","Hadoop"],
    'Fee' :[20000,25000,22000,24000,30000],
    'Duration':['30day','40days','35days','60days','55days'],
    'Discount':[1000,2300,2500,2000,3000]
              }
index_labels=['r1','r2','r3','r4','r5']
df = pd.DataFrame(technologies,index=index_labels)
print(df)

# Use DataFrame.iloc[] 
# To drop first three rows 
df2 = df.iloc[3:]
print(df2) 

# Use DataFrame.iloc[]
n = 3
df2 = df.iloc[n:]
print(df2)

# Use DataFrame.drop() function 
# To delete first three rows
df.drop(df.head(3).index, inplace=True)
print(df) 

# Use DataFrame.drop() function
df.drop(df.index[:3], inplace=True)
print(df) 

# Use DataFrame.tail() method 
# To drop first three rows
df2 = df.tail(-3)
print(df2)

Conclusion

In this article, you have learned about various methods for dropping the first three rows from a Pandas DataFrame. We explored techniques such as iloc[], drop(), and even repurposed tail() to achieve this task, supported by practical examples.

Happy Learning !!

References

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