objset: Add frozenset tests, skippable if frozenset not available.

tests/basics/frozenset1.py

+# basic sets
+
+try:
+    frozenset
+except NameError:
+    print("SKIP")
+    import sys
+    sys.exit()
+
+s = frozenset({1})
+print(s)
+
+s = frozenset({3, 4, 3, 1})
+print(sorted(s))

tests/basics/frozenset_add.py

+try:
+    frozenset
+except NameError:
+    print("SKIP")
+    import sys
+    sys.exit()
+
+s = frozenset({1, 2, 3, 4})
+try:
+    print(s.add(5))
+except AttributeError:
+    print("AttributeError")

tests/basics/frozenset_binop.py

+try:
+    frozenset
+except NameError:
+    print("SKIP")
+    import sys
+    sys.exit()
+
+sets = [
+    frozenset(), frozenset({1}), frozenset({1, 2}), frozenset({1, 2, 3}), frozenset({2, 3}),
+    frozenset({2, 3, 5}), frozenset({5}), frozenset({7})
+]
+for s in sets:
+    for t in sets:
+        print(sorted(s), '|', sorted(t), '=', sorted(s | t))
+        print(sorted(s), '^', sorted(t), '=', sorted(s ^ t))
+        print(sorted(s), '&', sorted(t), '=', sorted(s & t))
+        print(sorted(s), '-', sorted(t), '=', sorted(s - t))
+        u = s.copy()
+        u |= t
+        print(sorted(s), "|=", sorted(t), '-->', sorted(u))
+        u = s.copy()
+        u ^= t
+        print(sorted(s), "^=", sorted(t), '-->', sorted(u))
+        u = s.copy()
+        u &= t
+        print(sorted(s), "&=", sorted(t), "-->", sorted(u))
+        u = s.copy()
+        u -= t
+        print(sorted(s), "-=", sorted(t), "-->", sorted(u))
+
+        print(sorted(s), '==', sorted(t), '=', s == t)
+        print(sorted(s), '!=', sorted(t), '=', s != t)
+        print(sorted(s), '>', sorted(t), '=', s > t)
+        print(sorted(s), '>=', sorted(t), '=', s >= t)
+        print(sorted(s), '<', sorted(t), '=', s < t)
+        print(sorted(s), '<=', sorted(t), '=', s <= t)

tests/basics/frozenset_copy.py

+try:
+    frozenset
+except NameError:
+    print("SKIP")
+    import sys
+    sys.exit()
+
+s = frozenset({1, 2, 3, 4})
+t = s.copy()
+print(type(t))
+for i in s, t:
+    print(sorted(i))

tests/basics/frozenset_difference.py

+try:
+    frozenset
+except NameError:
+    print("SKIP")
+    import sys
+    sys.exit()
+
+l = [1, 2, 3, 4]
+s = frozenset(l)
+outs = [s.difference(),
+        s.difference(frozenset({1})),
+        s.difference(frozenset({1}), [1, 2]),
+        s.difference(frozenset({1}), {1, 2}, {2, 3})]
+for out in outs:
+    print(type(out), sorted(out))
+
+s = frozenset(l)
+try:
+    print(s.difference_update({1}))
+except AttributeError:
+    print("AttributeError")