如何从for循环创建列表

Question

everyone, recently I am trying to create a list from my data

Here is my data:

!wget --no-check-certificate 'https://drive.google.com/uc?export=download&id=1VfkX_asEXo1HpdSE68Cl_HEdyrKPDxsw' -O /content/API_UAT2.txt

I want to find whether these items exist in my data

tunnel_fares = {

            'Aberdeen Tunnel':5

                 , 'Lion Rock Tunnel':8

                 , 'Shing Mun Tunnels':5

                 , 'Tseung Kwan O Tunnel':3

                 , 'Tsing Sha Highway':8

                 , 'Cross Harbour Tunnel':20

                 , 'Eastern Harbour Crossing':40

                 , 'Western Harbour Crossing':85

            , 'Tate\'s Cairn Tunnel':20

            , 'Tai Lam Tunnel':48

            , 'Lantau Link':30

            }

Here is my code

with open ('API_UAT2.txt') as f:  #open the txt
    js = json.load(f) #turns it to json format
    data = js['routes'][0]['legs'][0]['steps']
    for item in data:
      data_name = item['name']
      toll = []
      for name,fare in tunnel_fares.items():
        if name in data_name:
          toll = name
          print(toll)

It finally returns

Western Harbour Crossing
Tsing Sha Highway
Tsing Sha Highway

However, I want to turn it into a list, and remove duplicated object ie:

['Western Harbour Crossing', 'Tsing Sha Highway']

I tried to use

new = list(map(lambda x:x, toll))

But it turns out a super weird thing. So how can I do this? Thank you very much.

Answer 1

To add an item to a list you would use:

toll.append(name)

instead of:

toll = name

Therefore your code will be:

with open ('API_UAT2.txt') as f:  #open the txt
    js = json.load(f) #turns it to json format
    data = js['routes'][0]['legs'][0]['steps']
    for item in data:
      data_name = item['name']
      toll = []
      for name,fare in tunnel_fares.items():
        if name in data_name:
          toll.append(name)
          print(toll)

Answer 2

Append to a list toll and remove duplicates using dict.fromkeys :

with open ('API_UAT2.txt') as f:  #open the txt
    js = json.load(f) #turns it to json format
    data = js['routes'][0]['legs'][0]['steps']
    for item in data:
      data_name = item['name']
      toll = []
      for name,fare in tunnel_fares.items():
        if name in data_name:
          toll.append(name)

toll = list(dict.fromkeys(toll))

Answer 3

You could use a set instead:

with open ('API_UAT2.txt') as f:  #open the txt
    js = json.load(f) #turns it to json format
    data = js['routes'][0]['legs'][0]['steps']
    tolls = set()
    for item in data:
      data_name = item['name']
      toll = []
      for name, fare in tunnel_fares.items():
        if name in data_name:
          tolls.add(name)

Answer 4

for removing duplicate items from list named l, you can use this code:

l = list(set(l))

Answer 5

Try this:

Code Syntax

with open ('API_UAT2.txt') as f:  #open the txt
    js = json.load(f) #turns it to json format
    data = js['routes'][0]['legs'][0]['steps']
    for item in data:
         data_name = item['name']
         toll = []
         for name,fare in tunnel_fares.items():
              if name in data_name:
                  toll.append(name)
         toll= list(set(toll))

         print(toll)

Output Syntax

['Western Harbour Crossing', 'Tsing Sha Highway']