我可以使用什么循环进行迭代，以便获得以下输出? [英] What loop can I use to iterate so that I can get the following output?

问题描述

这是我的代码.

def split_routes(routes_data):
    first_station = routes_data[0] #(’171’, ’1’, ’1’, ’59009’)
    curr_ser = first_station[1] #171
    for entry in routes_data:
        ser = entry[0]
        a = filter_routes(routes_data,"first_station[1]") # [(’171’, ’1’, ’1’, ’59009’), ... , (’171’, ’2’, ’73’, ’59009’)]
        x = tuple(["first_station[1]"] + [a])
        c = []   
        return c.append(x) 

filter_routes是先前定义的

filter_routes is previously defined

def filter_routes(routes_data, service_code):
    data = filter(lambda entry: entry[0] == service_code,
     routes_data)
    return data

print(filter_routes(bus_stations，"106")将返回

[('106', '1', '1', '43009'), ('106', '1', '2', '43179'), .... ('106', '2', '51', '43009')]

我知道这是错误的，因为我的输出应该是我 print(split_routes(bus_stations))时的输出这应该是输出.

I know it is wrong as my output should be when i print(split_routes(bus_stations)) This should be the output.

[(’171’, [(’171’, ’1’, ’1’, ’59009’), ... , (’171’, ’2’, ’73’, ’59009’)]),
 (’106’, [(’106’, ’1’, ’1’, ’43009’), ... , (’106’, ’2’, ’51’, ’43009’)]),
  (’184’, [(’184’, ’1’, ’1’, ’45009’), ... , (’184’, ’1’, ’52’, ’45009’)])]

routes_data = bus_stations这是一个看起来像这样的txt文件

routes_data = bus_stations here is a txt file that look like this

106,1,1,43009
.
.
.
106,2,51,43009
171,1,1,59009
.
.
.
171,2,73,59009
184,1,1,45009
.
.
.
184,1,52,45009

推荐答案

似乎您的问题是您将"first_station [1]" 用作字符串，而不使用其值.尝试致电
filter_routes(routes_data，first_station [1])
和
x =元组([first_station [1]] + [a])
另外，您仅使用第一个站，我的意思是要使用 ser 值，另一个问题是您需要先返回并退出函数，然后再将值存储在`resultz here这样的变量中，并在完成后返回:

seems like your problem is that you use "first_station[1]" as a string and not use its value. try call
filter_routes(routes_data,first_station[1])
and
x = tuple([first_station[1]] + [a])
in addition, you use only your first station, I thing you meant to use ser value, and another problem is that you return and quit the function before you finish, store the values in variable like `resultz here, and return it when you finish:

result = []
for entry in routes_data:
        ser = entry[0]
        a = filter_routes(routes_data,ser) 
        x = tuple([ser] + [a])
        result.append(x) 
return result

但是我会这样写:

def split_routes(routes_filename):
    stations = {}
    with open(routes_filename,"r") as routes_data:
        for line in routes_data:
            vals = line.strip().split(",") # [’171’, ’1’, ’1’, ’59009’]
            stations.setdefault(vals[0],[]).append(vals)
    result = []
    for st in stations:
        result.append((st,stations[st]))
    return result

并使用文件名进行调用:

and call it with the filename:

split_routes("bus_stations.txt")

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