Step-by-Step Guide to Creating and Using Pandas DataFrames

DataFrames and Pandas are core components of Python for data analysis and manipulation.

Pandas Library

Pandas is a powerful and flexible Python library that provides tools for working with structured data, such as tables or spreadsheets. It’s particularly well-suited for data cleaning, transformation, and exploratory data analysis.

DataFrame

A DataFrame is the primary data structure in Pandas. It is a two-dimensional, size-mutable, and labeled data structure, similar to a table in a relational database, an Excel spreadsheet, or a NumPy array with labeled rows and columns.

Key Features of DataFrames:

1. Labeled Rows and Columns: Rows are indexed, and columns have names.
2. Flexible Data Storage: Handles diverse data types (numeric, string, boolean, etc.).
3. Powerful Operations: Enables filtering, aggregating, joining, reshaping, and more.
4. Integration: Can easily read and write to multiple formats like CSV, Excel, SQL, and JSON.

Example Usage

Here’s a quick guide to getting started with Pandas and DataFrames:

1. Importing Pandas

import pandas as pd

2. Creating a DataFrame(manually or load it from external data sources)

From a Dictionary:

data = {

    ‘Name’: [‘yuva’, ‘ganapati’, ‘Charlie’],

    ‘Age’: [25, 30, 35],

    ‘Salary’: [50000, 60000, 70000]

}

df = pd.DataFrame(data)

print(df)

Output:

      Name  Age  Salary

0    Yuva   25   50000

1   Ganapati30   60000

2   Charlie   35   70000

3. Basic Operations

Access Columns:

print(df[‘Name’])  # Access the ‘Name’ column

Filter Rows:

print(df[df[‘Age’] > 25])

Add a New Column:

df[‘Bonus’] = df[‘Salary’] * 0.1

print(df)

Summary Statistics

print(df.describe())  # Summary statistics of numeric columns

4. Loading and Saving Data

Read CSV File:

df = pd.read_csv(‘data.csv’)

Save DataFrame to CSV:

df.to_csv(‘output.csv’, index=False)

5. Advanced Operations

• Group By: Aggregate data by categories.
• Merging and Joining: Combine multiple DataFrames.
• Reshaping: Pivot tables and melting.