如何使用PYTHON访问保存为JSON中的键列表的所有词典的第一个键的值

Question

I have the JSON which looks like this:-

{
        "name": "PT",
        "batservers": [
            {"name": "bat1", "qmchannel": "abcd", "mount": "efgh"},
            {"name": "bat2", "qmchannel": "abcd", "mount": "efgh"},
            {"name": "bat3", "qmchannel": "abcd", "mount": "efgh"},
        ]
    }

I want to retrieve the value of "name" present in all the dictionary and save it in a list variable ie ["bat1","bat2","bat3"]

I tried something like this:-

batsList = env["batservers"][0:]["name"]

but it displays the below error:-

TypeError: list indices must be integers or slices, not str

I know I can do this using a loop but can someone please help me to do using in a single line code way which I am trying above?

Thanks, SUYASH GUPTA.

Answer 1

You can't do it without a loop. But the loop can be a list comprehension:

batsList = [b['name'] for b in env["batservers"]

Answer 2

How about saving the list as:

list_of_names = [x[name] for x in env["batservers"]]

Answer 3

Try this:

[b['name'] for b in env['batservers']]

Or this:

map(lambda b: b['name'], env['batservers'])

[0:] doesn't do much for you: it returns the same array of dictionaries.

Answer 4

env["batservers"][0:] returns a list, and you can't access directly the values of the dicts in the list.

You can use a list comprehension:

names = [elem["name"] for elem in env["batservers"]]

Answer 5

This is a basic solution using a for loop to iterate over the sub dictionary and appending to the empty list res .

res = []
for item in env["batservers"]:
  res.append(item["name"])

print (res) #=> ['bat1', 'bat2', 'bat3']