Post #1662

Common Data Cleaning Techniques for Data Analysts Remove Duplicates: Purpose: Eliminate repeated rows to maintain unique data. Example: SELECT DISTINCT column_name FROM table; Handle Missing Values: Purpose: Fill, remove, or impute missing data. Example: Remove: df.dropna() (in Python/Pandas) Fill: df.fillna(0) Standardize Data: Purpose: Convert data to a consistent format (e.g., dates, numbers). Example: Convert text to lowercase: df['column'] = df['column'].str.lower() Remove Outliers: Purpose: Identify and remove extreme values. Example: df = df[df['column'] < threshold] Correct Data Types: Purpose: Ensure columns have the correct data type (e.g., dates as datetime, numeric values as integers). Example: df['date'] = pd.to_datetime(df['date']) Normalize Data: Purpose: Scale numerical data to a standard range (0 to 1). Example: from sklearn.preprocessing import MinMaxScaler; df['scaled'] = MinMaxScaler().fit_transform(df[['column']]) Data Transformation: Purpose: Transform or aggregate data for better analysis (e.g., log transformations, aggregating columns). Example: Apply log transformation: df['log_column'] = np.log(df['column'] + 1) Handle Categorical Data: Purpose: Convert categorical data into numerical data using encoding techniques. Example: df['encoded_column'] = pd.get_dummies(df['category_column']) Impute Missing Values: Purpose: Fill missing values with a meaningful value (e.g., mean, median, or a specific value). Example: df['column'] = df['column'].fillna(df['column'].mean()) Data Cleaning: https://whatsapp.com/channel/0029VarxgFqATRSpdUeHUA27 Like this post for more content like this 👍♥️ Share with credits: https://t.me/sqlspecialist Hope it helps :)