Set Operations

def union(*frames) -> Frame:
    """
    Union of data frames (all unique rows from all frames).
    
    Parameters:
    - *frames: Frame objects to combine
    
    Returns:
    Frame with all unique rows from input frames
    """

def intersect(*frames) -> Frame:
    """
    Intersection of data frames (rows common to all frames).
    
    Parameters:
    - *frames: Frame objects to intersect
    
    Returns:
    Frame with rows present in all input frames
    """

def setdiff(frame1, frame2) -> Frame:
    """
    Set difference (rows in frame1 but not in frame2).
    
    Parameters:
    - frame1: First Frame
    - frame2: Second Frame
    
    Returns:
    Frame with rows in frame1 that are not in frame2
    """

def symdiff(frame1, frame2) -> Frame:
    """
    Symmetric difference (rows in either frame but not both).
    
    Parameters:
    - frame1: First Frame
    - frame2: Second Frame
    
    Returns:
    Frame with rows in either frame but not in both
    """

import datatable as dt

# Create sample frames
A = dt.Frame({'x': [1, 2, 3], 'y': ['a', 'b', 'c']})
B = dt.Frame({'x': [2, 3, 4], 'y': ['b', 'c', 'd']})
C = dt.Frame({'x': [3, 4, 5], 'y': ['c', 'd', 'e']})

# Union - all unique rows
union_AB = dt.union(A, B)
union_ABC = dt.union(A, B, C)

# Intersection - common rows
intersect_AB = dt.intersect(A, B)
intersect_ABC = dt.intersect(A, B, C)

# Set difference
diff_AB = dt.setdiff(A, B)  # Rows in A but not B
diff_BA = dt.setdiff(B, A)  # Rows in B but not A

# Symmetric difference
symdiff_AB = dt.symdiff(A, B)  # Rows in A or B but not both