Importing/Exporting Data between CSV files and Data Frames.

Importing/Exporting Data between CSV files and Data Frames.

For a class 12 level, we'll focus on the basics of importing and exporting data between CSV files and DataFrames using Python with the pandas library. This is a common and practical skill in data handling and is straightforward with the right tools.

Python with pandas

pandas is a powerful library in Python that provides data structures and data analysis tools. Here’s a step-by-step guide on how to work with CSV files and DataFrames using pandas.

1. Importing Data from a CSV File to a DataFrame

Step-by-Step:

1. Install pandas (if not already installed):

   pip install pandas
   

2. Import pandas in your Python script:

   import pandas as pd
   

3. Read data from a CSV file:

   
   # Specify the path to your CSV file
   file_path = 'data.csv'
   # Load the CSV file into a DataFrame
   df = pd.read_csv(file_path)
   # Display the first few rows of the DataFrame
   print(df.head())

   Explanation:

   • pd.read_csv(file_path) reads the CSV file and loads it into a DataFrame named df.
   • df.head() shows the first 5 rows of the DataFrame, which helps you verify that the data has been loaded correctly.

2. Exporting Data from a DataFrame to a CSV File

Step-by-Step:

1. Create a DataFrame:

   
   # Create a sample DataFrame
   data = {
       'Name': ['Alice', 'Bob', 'Charlie'],
       'Age': [25, 30, 35]
   }
   df = pd.DataFrame(data)

2. Export the DataFrame to a CSV file:

   
   # Specify the path to save the CSV file
   file_path = 'output.csv'
   # Write the DataFrame to a CSV file
   df.to_csv(file_path, index=False)
   # `index=False` prevents writing row indices to the file

   Explanation:

   • df.to_csv(file_path, index=False) saves the DataFrame to a CSV file named output.csv.
   • index=False ensures that the row indices are not included in the CSV file.

Summary

• Importing Data: Use pd.read_csv('file_path') to read a CSV file into a DataFrame.
• Exporting Data: Use df.to_csv('file_path', index=False) to write a DataFrame to a CSV file.