动态定义多维字典

# 动态定义一个二维字典
multi_dim_dict = {}

# 添加数据
multi_dim_dict['row1'] = {'col1': 1, 'col2': 2}
multi_dim_dict['row2'] = {'col1': 3, 'col2': 4}

print(multi_dim_dict)

# 修改数据
multi_dim_dict['row1']['col1'] = 10

print(multi_dim_dict)

# 动态添加新行
multi_dim_dict['row3'] = {'col1': 5, 'col2': 6}

print(multi_dim_dict)

# 使用 get 方法
value = multi_dim_dict.get('row1', {}).get('col1', 0)
print(value)  # 输出 10

# 使用 defaultdict
from collections import defaultdict

multi_dim_dict = defaultdict(lambda: defaultdict(int))
multi_dim_dict['row1']['col1'] = 10
value = multi_dim_dict['row1']['col1']
print(value)  # 输出 10

for row_key, row_value in multi_dim_dict.items():
    for col_key, col_value in row_value.items():
        print(f"Row: {row_key}, Col: {col_key}, Value: {col_value}")