Eda

What I do

• Explore datasets to understand structure
• Identify patterns and relationships
• Detect anomalies and outliers
• Generate summary statistics
• Create visualizations for data understanding
• Form and test hypotheses
• Guide feature selection for modeling

When to use me

Use me when:

• Starting a new data analysis project
• Understanding data before modeling
• Identifying data quality issues
• Discovering patterns in data
• Preparing for feature engineering

Key Concepts

EDA Process

1. Data Collection: Load and understand data
2. Data Description: Summary statistics
3. Data Cleaning: Handle missing, outliers
4. Univariate Analysis: Single variable patterns
5. Bivariate Analysis: Relationships between variables
6. Multivariate Analysis: Complex relationships

Python EDA Example

import pandas as pd
import numpy as np
import seaborn as sns
import matplotlib.pyplot as plt

# Load data
df = pd.read_csv("data.csv")

# Basic statistics
print(df.describe())
print(df.dtypes)
print(df.isnull().sum())

# Distribution analysis
fig, axes = plt.subplots(2, 2, figsize=(12, 10))

# Histogram
sns.histplot(df["age"], kde=True, ax=axes[0, 0])

# Box plot for outliers
sns.boxplot(x="income", y="education", data=df, ax=axes[0, 1])

# Correlation heatmap
corr = df.select_dtypes(include=[np.number]).corr()
sns.heatmap(corr, annot=True, cmap="coolwarm", ax=axes[1, 0])

# Scatter with regression
sns.regplot(x="age", y="income", data=df, ax=axes[1, 1])

plt.tight_layout()
plt.show()

# Categorical analysis
print(df["category"].value_counts())
print(pd.crosstab(df["category"], df["outcome"]))

Key Metrics

• Central tendency: Mean, median, mode
• Spread: Std dev, variance, IQR
• Shape: Skewness, kurtosis
• Correlation: Pearson, Spearman