Data manipulation is a critical skill in data analysis. Here are essential techniques to master:
🔍 1. Data Cleaning
- Remove duplicates: Use
drop_duplicates()
in pandas. - Handle missing values: Replace
NaN
with interpolation or forward fill. - Correct inconsistencies: Standardize formats (e.g., dates, currencies).Data Cleaning
🔄 2. Data Transformation
- Normalize data using Min-Max scaling:
(X - min) / (max - min)
- Encode categorical variables with one-hot encoding.
- Apply logarithmic transformations for skewed distributions.Data Transformation
📊 3. Data Aggregation
- Group data by categories and calculate summary statistics:
SELECT category, AVG(value) FROM table GROUP BY category;
- Use pivot tables to reshape datasets.
- Merge datasets using
JOIN
operations.Data Aggregation
🧠 4. Advanced Techniques
- Feature engineering: Create new variables from existing data.
- Resampling: Upsample or downsample datasets for balance.
- Dimensionality reduction: Apply PCA or t-SNE.Dimensionality Reduction
For deeper insights, explore our Data Processing Fundamentals guide. 🚀
Data Processing