Question

我有一个字典，显示一个人的旅行，其中空白列表表示步行，列表包含内容表示他/她采取的管。我想找出他/她的第一次管道旅程，其编号为＆＃39; 2,3＆＃39;。

specific_path_legs={0: [],
 1: [],
 2: ['Jubilee'],
 3: ['Jubilee'],
 4: [],
 5: [],
 6: ['Metropolitan'],
 7: ['Metropolitan'],
 8: ['Metropolitan'],
 9: ['Metropolitan'],
 10: [],
 11: [],
 12: [],
 13: [],
 14: ['Northern'],
 15: ['Northern'],
 16: ['Northern'],
 17: ['Northern'],
 18: ['Northern'],
 19: [],
 20: [],
 21: [],
 22: ['Jubilee'],
 23: ['Jubilee'],
 24: ['Jubilee'],
 25: [],
 26: [],
 27: []}

我首先排除了walk部分并获得了leg_nonempty字典。

legs_nonempty={2: ['Jubilee'],
  3: ['Jubilee'],
 6: ['Metropolitan'],
 7: ['Metropolitan'],
 8: ['Metropolitan'],
 9: ['Metropolitan'],
 14: ['Northern'],
 15: ['Northern'],
 16: ['Northern'],
 17: ['Northern'],
 18: ['Northern'],
 22: ['Jubilee'],
 23: ['Jubilee'],
 24: ['Jubilee']}

然后我试了

first_leg=[]
for key,value in specific_path_legs.items():
    if value==legs_nonempty.itervalues().next():
        first_leg.append(key)

但它返回了

first_leg=[2,3, 22, 23, 24]

我只需要[2,3]而不是[2,3,22,23,24]。有什么想法吗？

Answer 1

# Sort dictionary based on keys
import collections
specific_path_legs = collections.OrderedDict(sorted(specific_path_legs.items()))

# Store your info in another dict
path_legs_dict = {}
for key, value in specific_path_legs.items():
    if value and value[0] not in path_legs_dict:
        path_legs_dict[value[0]] = key

print path_legs_dict
# Output: {'Jubilee': 2, 'Northern': 14, 'Metropolitan': 6}

我正在使用collections.OrderedDict因为python中的默认dict对象没有被排序。

Answer 2

由于键是从0开始递增的，所以直到找到非空值：

for i in range(len(specific_path_legs)):
    if specific_path_legs[i]:
        print(i, specific_path_legs[i])
        break

哪会给你：

(2, ['Jubilee'])

如果您还想匹配特定值：

for i in range(len(specific_path_legs)):
    val = specific_path_legs[i]
    if val and val == "Jubilee":
        print(i ,specific_path_legs[i]
        break

根据字典中的值查找第一个相同组的索引

2 个答案: