回顾:自定义列表
本课属于 Coddy Python 学习旅程的“面向对象编程”单元。第 36 课,共 64 课。
挑战
中等在这个挑战中,你将实现一个功能完整的 CustomList 类,使其行为与 Python 内置列表相似,同时展示你对特殊方法的理解。
只需按照 TODO 注释的指引,逐步编辑 customlist.py 文件。
你的实现应支持:
- 使用可选项进行初始化
- 索引(获取和设置值)
- 使用
len()检查长度 - 与其他列表相加
- 字符串表示
- 迭代和成员检查
- 方法:
append、pop和clear
亲手试试
from customlist import CustomList
def test_basic_functionality():
"""Test basic CustomList functionality"""
try:
# 测试初始化
empty_list = CustomList()
assert len(empty_list) == 0, f"Empty list should have length 0, but has {len(empty_list)}"
init_list = CustomList([1, 2, 3])
assert len(init_list) == 3, f"Initialized list should have length 3, but has {len(init_list)}"
# 测试索引访问
assert init_list[0] == 1, f"First element should be 1, but got {init_list[0]}"
init_list[1] = 10
assert init_list[1] == 10, f"Element after assignment should be 10, but got {init_list[1]}"
# 测试字符串表示形式
assert str(init_list) == "[1, 10, 3]", f"String representation incorrect, got {str(init_list)}"
# 测试加法运算
combined = init_list + CustomList([4, 5])
assert len(combined) == 5, f"Combined list should have length 5, but has {len(combined)}"
assert combined[3] == 4, f"Fourth element of combined list should be 4, but got {combined[3]}"
# 测试迭代和成员检查
items = []
for item in combined:
items.append(item)
assert items == [1, 10, 3, 4, 5], f"Iteration produced incorrect items: {items}"
assert 10 in combined, "10 should be in the list"
assert 7 not in combined, "7 should not be in the list"
# 测试 append 和 pop
combined.append(6)
assert len(combined) == 6, f"After append, length should be 6, but got {len(combined)}"
assert combined[5] == 6, f"Last element after append should be 6, but got {combined[5]}"
popped = combined.pop()
assert popped == 6, f"Popped value should be 6, but got {popped}"
assert len(combined) == 5, f"After pop, length should be 5, but got {len(combined)}"
# 测试 clear
combined.clear()
assert len(combined) == 0, f"After clear, length should be 0, but got {len(combined)}"
print("Basic functionality tests passed!")
return True
except Exception as e:
print(f"Basic functionality test failed: {e}")
return False
def test_edge_cases():
"""Test edge cases and boundary conditions"""
try:
# 测试空列表操作
empty_list = CustomList()
# 测试对空列表执行 pop
try:
empty_list.pop()
assert False, "pop() on empty list should raise IndexError"
except IndexError:
pass # 预期行为
# 测试对空列表进行索引访问
try:
value = empty_list[0]
assert False, "Indexing empty list should raise IndexError"
except IndexError:
pass # 预期行为
# 测试包含 None 值的列表
none_list = CustomList([None, None])
assert len(none_list) == 2, f"List with None values should have length 2, got {len(none_list)}"
assert none_list[0] is None, "First element should be None"
# 测试混合数据类型
mixed_list = CustomList([1, "string", 3.14, [1, 2], {"key": "value"}])
assert len(mixed_list) == 5, f"Mixed type list should have length 5, got {len(mixed_list)}"
assert mixed_list[1] == "string", f"Second element should be 'string', got {mixed_list[1]}"
# 测试与普通列表相加
result = mixed_list + [6, 7, 8]
assert len(result) == 8, f"After adding regular list, length should be 8, got {len(result)}"
assert result[5] == 6, f"Sixth element should be 6, got {result[5]}"
# 测试与空列表相加
result = mixed_list + []
assert len(result) == 5, f"After adding empty list, length should be 5, got {len(result)}"
assert result[0] == 1, f"First element should still be 1, got {result[0]}"
# 测试 repr
repr_str = repr(CustomList([1, 2, 3]))
assert repr_str == "CustomList([1, 2, 3])", f"repr should be 'CustomList([1, 2, 3])', got {repr_str}"
print("Edge case tests passed!")
return True
except Exception as e:
print(f"Edge case test failed: {e}")
return False
def test_large_lists():
"""Test performance with large lists"""
try:
# 创建大型列表并测试相关操作
# 创建大型列表
large_list = CustomList(range(10000))
assert len(large_list) == 10000, f"Large list should have length 10000, got {len(large_list)}"
# 测试大型列表的索引操作
assert large_list[9999] == 9999, f"Last element should be 9999, got {large_list[9999]}"
# 测试大型列表的包含关系
assert 5000 in large_list, "5000 should be in the large list"
assert 10001 not in large_list, "10001 should not be in the large list"
# 测试两个大型列表相加
other_large = CustomList(range(10000, 20000))
combined = large_list + other_large
assert len(combined) == 20000, f"Combined large lists should have length 20000, got {len(combined)}"
assert combined[0] == 0, f"First element should be 0, got {combined[0]}"
assert combined[19999] == 19999, f"Last element should be 19999, got {combined[19999]}"
print("Large list tests passed!")
return True
except Exception as e:
print(f"Large list test failed: {e}")
return False
def test_nested_lists():
"""Test with nested CustomList objects"""
try:
# 测试嵌套的 CustomList 对象
inner1 = CustomList([1, 2, 3])
inner2 = CustomList([4, 5, 6])
outer = CustomList([inner1, inner2, 7])
assert len(outer) == 3, f"Outer list should have length 3, got {len(outer)}"
assert outer[0] is inner1, "First element should be inner1"
assert len(outer[0]) == 3, f"First inner list should have length 3, got {len(outer[0])}"
assert outer[0][1] == 2, f"Second element of first inner list should be 2, got {outer[0][1]}"
# 测试修改内部列表
inner1.append(4)
assert len(outer[0]) == 4, f"After append, inner list should have length 4, got {len(outer[0])}"
assert outer[0][3] == 4, f"Fourth element of inner list should be 4, got {outer[0][3]}"
# 测试嵌套列表相加
result = outer[0] + outer[1]
assert len(result) == 7, f"Combined inner lists should have length 7, got {len(result)}"
assert result[0] == 1, f"First element should be 1, got {result[0]}"
assert result[6] == 6, f"Last element should be 6, got {result[6]}"
print("Nested list tests passed!")
return True
except Exception as e:
print(f"Nested list test failed: {e}")
return False
def test_custom_operations():
"""Test custom operations and combinations"""
try:
# 测试自定义操作和方法组合
# 测试链式操作
list1 = CustomList([1, 2])
list2 = CustomList([3, 4])
list3 = CustomList([5, 6])
# 连续相加
result = list1 + list2 + list3
assert len(result) == 6, f"Chained addition should have length 6, got {len(result)}"
assert result[5] == 6, f"Last element should be 6, got {result[5]}"
# 测试依次调用 append 和 pop
test_list = CustomList([1, 2, 3])
test_list.append(4)
test_list.append(5)
assert test_list.pop() == 5, "First pop should return 5"
assert test_list.pop() == 4, "Second pop should return 4"
assert len(test_list) == 3, f"After two pops, length should be 3, got {len(test_list)}"
# 测试先调用 clear,再调用 append
test_list.clear()
assert len(test_list) == 0, f"After clear, length should be 0, got {len(test_list)}"
test_list.append(10)
assert len(test_list) == 1, f"After append to cleared list, length should be 1, got {len(test_list)}"
assert test_list[0] == 10, f"Element should be 10, got {test_list[0]}"
# 测试空列表相加
empty1 = CustomList()
empty2 = CustomList()
empty_sum = empty1 + empty2
assert len(empty_sum) == 0, f"Sum of empty lists should be empty, got length {len(empty_sum)}"
print("Custom operations tests passed!")
return True
except Exception as e:
print(f"Custom operations test failed: {e}")
return False
# 运行选定的测试或所有测试
test_case = input()
if test_case == "basic":
test_basic_functionality()
elif test_case == "edge":
test_edge_cases()
elif test_case == "large":
test_large_lists()
elif test_case == "nested":
test_nested_lists()
elif test_case == "custom":
test_custom_operations()
else:
print("Invalid test case. Running basic tests by default.")
test_basic_functionality()面向对象编程中的所有课
自己练习: Python 在线编译器