- .pivot() - Long to wide format
- .pivot_table() - Pivot with aggregation
- .melt() - Wide to long transformation
- .stack() / .unstack() - Index manipulation
- .crosstab() - Cross-tabulation tables
- .transpose() / .T - Matrix transposition
- .explode() - Expand list-like columns
- .concat() - Concatenate DataFrames
- .merge() - SQL-style joins
- .join() - Index-based joining
- .groupby().agg(custom_function) - Complex ops
- .groupby().apply(col='sum') - Multi agg
- .groupby().transform() - Broadcast back
- .groupby().filter() - Group filtering
- .groupby().rolling() - Rolling within groups
- .groupby().nth() - Get nth row per group
- .groupby().head() / .tail() - First/last n rows
- .groupby().size() vs .count() - Differences
- .sum() / .mean() / .std() - Basic aggregation
- .value_counts() - Frequency analysis
- .str.extract() - Regex pattern extraction
- .str.split() + .str.get() - String parsing
- .str.replace() - Regex replacements
- .str.contains() - Complex patterns
- .str.findall() - Find all matches
- .fillna() / .dropna() - Handle missing values
- .duplicated() / .drop_duplicates() - Clean duplicates
- .isna() / .notna() - Missing data detection
- .drop() - Remove columns/rows
- .rename() - Rename columns/index
- .xs() - Cross-section from MultiIndex
- .query() - SQL-like filtering syntax
- .eval() - Expression evaluation
- .where() / .mask() - Conditional selection
- MultiIndex operations
- .loc[] / .iloc[] - Label/position indexing
- .at[] / .iat[] - Single value access
- .set_index() / .reset_index() - Index manipulation
- .reindex() - Conform to new index
- .sort_values() / .sort_index() - Sorting
- astype('category') - Categorical data
- .cut() / .qcut() - Binning continuous data
- pd.get_dummies() - One-hot encoding
- .factorize() - Convert to numeric codes
- Categorical operations (.cat accessor)
- .select_dtypes() - Filter columns by type
- .convert_dtypes() - Auto type inference
- .info() / .describe() - Data overview
- .dtypes / .shape - Basic properties
- .memory_usage() - Memory profiling
- .resample() - Time-based grouping
- .rolling() - Custom windows
- .expanding() - Expanding windows
- pd.date_range() - Complex frequencies
- Advanced datetime indexing
- .tz_localize() / .tz_convert() - Timezone handling
- .dt accessor methods - Date/time operations
- .interpolate() - Smart missing value filling
- .head() / .tail() / .sample() - Data sampling
- .corr() / .cov() - Statistical relationships