Optimize reading large Excel files with Pandas
Pandas: Performance Optimization Exercise-20 with Solution
Write a Pandas program to optimize the performance of reading a large Excel file into a DataFrame by specifying data types and using the 'usecols' parameter.
Sample Solution :
Python Code :
# Import necessary libraries
import pandas as pd
# Specify the path to the large Excel file
file_path = 'large_excel_file.xlsx'
# Define the data types for the columns
dtypes = {
'Column1': 'int64',
'Column2': 'float64',
'Column3': 'object',
# Add more column types as needed
}
# Define the columns to read
usecols = ['Column1', 'Column2', 'Column3']
# Use read_excel with specified data types and columns to read
df = pd.read_excel(file_path, dtype=dtypes, usecols=usecols)
# Display the DataFrame
print(df.head())
Output:
Column1 Column2 Column3 0 1 1.1 abcd 1 2 1.2 abcd 2 3 1.3 abcd 3 4 1.4 abcd 4 5 1.5 abcd
Explanation:
- Import necessary libraries:
- Import pandas.
- Specify the path to the large Excel file:
- The file path is set to a variable.
- Define the data types for the columns:
- A dictionary specifying the data types for each column.
- Define the columns to read:
- A list of column names to be read from the Excel file.
- Read the Excel file:
- Use pd.read_excel with the dtype and usecols parameters to optimize performance.
- Display the DataFrame:
- Print the first few rows of the DataFrame to confirm successful loading.
Python-Pandas Code Editor:
Have another way to solve this solution? Contribute your code (and comments) through Disqus.
Previous: Efficiently apply multiple Aggregation functions in Pandas.
What is the difficulty level of this exercise?
Test your Programming skills with w3resource's quiz.
- Weekly Trends and Language Statistics
- Weekly Trends and Language Statistics