Python辞書DICT型マージの詳しい説明

key = ['success', 'dangerous']
value = ''

# 返回的list
result_list = []
index = 0
while index < 4:
 # 中间字典，存储数据，以及防止append覆盖
 result_dict = {}
 _key = key[0]
 value = str(index)
 result_dict[_key] = value
 index = index + 1
 result_list.append(result_dict)
index = 0
return_list = []
print result_list
while index < 4:
 # 中间字典，存储数据，以及防止append覆盖
 result_dict = {}
 _key = key[1]
 value = str(index)
 result_dict[_key] = value
 dictMerge = dict(result_list[index].items() + result_dict.items())
 return_list.append(dictMerge)
 index = index + 1
print return_list