Skip to content

Add more tests to csp.py #328

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
norvig merged 1 commit into from
Mar 18, 2017
Merged

Add more tests to csp.py #328

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
88 changes: 88 additions & 0 deletions tests/test_csp.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -166,6 +166,94 @@ def test_csp_conflicted_vars():
assert (conflicted_vars == ['B', 'C'] or conflicted_vars == ['C', 'B'])


def test_revise():
neighbors = parse_neighbors('A: B; B: ')
domains = {'A': [0], 'B': [4]}
constraints = lambda X, x, Y, y: x % 2 == 0 and (x+y) == 4

csp = CSP(variables=None, domains=domains, neighbors=neighbors, constraints=constraints)
csp.support_pruning()
Xi = 'A'
Xj = 'B'
removals = []

assert revise(csp, Xi, Xj, removals) is False
assert len(removals) == 0

domains = {'A': [0, 1, 2, 3, 4], 'B': [0, 1, 2, 3, 4]}
csp = CSP(variables=None, domains=domains, neighbors=neighbors, constraints=constraints)
csp.support_pruning()

assert revise(csp, Xi, Xj, removals) is True
assert removals == [('A', 1), ('A', 3)]


def test_AC3():
neighbors = parse_neighbors('A: B; B: ')
domains = {'A': [0, 1, 2, 3, 4], 'B': [0, 1, 2, 3, 4]}
constraints = lambda X, x, Y, y: x % 2 == 0 and (x+y) == 4 and y % 2 != 0
removals = []

csp = CSP(variables=None, domains=domains, neighbors=neighbors, constraints=constraints)

assert AC3(csp, removals=removals) is False

constraints = lambda X, x, Y, y: (x % 2) == 0 and (x+y) == 4
removals = []
csp = CSP(variables=None, domains=domains, neighbors=neighbors, constraints=constraints)

assert AC3(csp, removals=removals) is True
assert (removals == [('A', 1), ('A', 3), ('B', 1), ('B', 3)] or
removals == [('B', 1), ('B', 3), ('A', 1), ('A', 3)])


def test_first_unassigned_variable():
map_coloring_test = MapColoringCSP(list('123'), 'A: B C; B: C; C: ')
assignment = {'A': '1', 'B': '2'}
assert first_unassigned_variable(assignment, map_coloring_test) == 'C'

assignment = {'B': '1'}
assert (first_unassigned_variable(assignment, map_coloring_test) == 'A' or
first_unassigned_variable(assignment, map_coloring_test) == 'C')


def test_num_legal_values():
map_coloring_test = MapColoringCSP(list('123'), 'A: B C; B: C; C: ')
map_coloring_test.support_pruning()
var = 'A'
assignment = {}

assert num_legal_values(map_coloring_test, var, assignment) == 3

map_coloring_test = MapColoringCSP(list('RGB'), 'A: B C; B: C; C: ')
assignment = {'A': 'R', 'B': 'G'}
var = 'C'

assert num_legal_values(map_coloring_test, var, assignment) == 1


def test_mrv():
neighbors = parse_neighbors('A: B; B: C; C: ')
domains = {'A': [0, 1, 2, 3, 4], 'B': [4], 'C': [0, 1, 2, 3, 4]}
constraints = lambda X, x, Y, y: x % 2 == 0 and (x+y) == 4
csp = CSP(variables=None, domains=domains, neighbors=neighbors, constraints=constraints)
assignment = {'A': 0}

assert mrv(assignment, csp) == 'B'

domains = {'A': [0, 1, 2, 3, 4], 'B': [0, 1, 2, 3, 4], 'C': [0, 1, 2, 3, 4]}
csp = CSP(variables=None, domains=domains, neighbors=neighbors, constraints=constraints)

assert (mrv(assignment, csp) == 'B' or
mrv(assignment, csp) == 'C')

domains = {'A': [0, 1, 2, 3, 4], 'B': [0, 1, 2, 3, 4, 5, 6], 'C': [0, 1, 2, 3, 4]}
csp = CSP(variables=None, domains=domains, neighbors=neighbors, constraints=constraints)
csp.support_pruning()

assert mrv(assignment, csp) == 'C'


def test_backtracking_search():
assert backtracking_search(australia)
assert backtracking_search(australia, select_unassigned_variable=mrv)
Expand Down