Revise my python code.

Please help me check my python code for this question as follow:

Please follow the question from my attached image.

domains = {
    'V1': [1, 2, 3,4],
    'V2': [1, 2, 3,4],
    'V3': [1, 2, 3,4],
    'V4': [1, 2, 3,4],
    'V5': [1, 2, 3,4],
    'V6': [1, 2, 3,4],
    'V7': [1, 2, 3,4],
    'V8': [1, 2, 3,4]
}

constraints = {
    ('V8', 'V1'): lambda v8, v1: v8 <= v1,
    ('V1', 'V2'): lambda v1, v2: v1 < v2,
    ('V2', 'V4'): lambda v2, v4: v2 != v4,
    ('V2', 'V3'): lambda v2, v3: v2 == v3,
    ('V4', 'V5'): lambda v4, v5: v4 == v5,
    ('V3', 'V5'): lambda v3, v5: v3 < v5,
    ('V6', 'V3'): lambda v6, v3: v6 < v3,
    ('V6', 'V5'): lambda v6, v5: v6 != v5,
    ('V7', 'V3'): lambda v7, v3: v7 < v3,
    ('V7', 'V6'): lambda v7, v6: v7 <= v6,
    ('V1', 'V7'): lambda v1, v7: v1 <= v7,
    ('V8', 'V7'): lambda v8, v7: v8 == v7
}
def revise(x, y):
    """
    Make variable `x` arc consistent with variable `y`.
    To do so, remove values from `domains[x]` for which there is no
    possible corresponding value for `y` in `domains[y]`.

    Return True if a revision was made to the domain of `x`; return
    False if no revision was made.
    """
    revised = False

    # Get x and y domains
    x_domain = domains[x]
    y_domain = domains[y]

    # Get all arc (x, y) constraints
    all_constraints = [
        constraint for constraint in constraints if constraint[0] == x and constraint[1] == y]

    for x_value in x_domain:
        satisfies = False
        for y_value in y_domain:
            for constraint in all_constraints:
                constraint_func = constraints[constraint]
                if constraint_func(x_value, y_value):
                    satisfies = True
        if not satisfies:
            x_domain.remove(x_value)
            revised = True

    return revised
def ac3(arcs):
    """
    Update `domains` such that each variable is arc consistent.
    """
    # Add all the arcs to a queue.
    queue = arcs[:]

    # Repeat until the queue is empty
    while queue:
        # Take the first arc off the queue (dequeue)
        (x, y) = queue.pop(0)

        # Make x arc consistent with y
        revised = revise(x, y)

        # If the x domain has changed
        if revised:
            # Add all arcs of the form (k, x) to the queue (enqueue)
            neighbors = [neighbor for neighbor in arcs if neighbor[1] == x]
            queue = queue + neighbors
arcs = [ ('V8', 'V1'),  ('V1', 'V2'), ('V2', 'V4'), ('V2', 'V3'), ('V4', 'V5'), ('V3', 'V5'), ('V6', 'V3'), ('V6', 'V5'), ('V7', 'V3'), ('V7', 'V6'), ('V1', 'V7'), ('V8', 'V7')]

ac3(arcs)

print(domains) #