如何从python中的多个字典中获取一个键的值？

Question

This is the data I have in my data.txt file

{"setup": "test", "punchline": "ok", "numOfRatings": 0, "sumOfRatings": 0},
{"setup": "test2", "punchline": "ok2", "numOfRatings": 0, "sumOfRatings": 0}

How would I be able to get only data from every setup in the dictionaries using a loop?

Thanks

Answer 1

I'm not sure how you're getting the dictionaries into your text file in the first place, but if it's possible to drop the trailing commas, ie

{"setup": "test", "punchline": "ok", "numOfRatings": 0, "sumOfRatings": 0}
{"setup": "test2", "punchline": "ok2", "numOfRatings": 0, "sumOfRatings": 0}

Something like this may work for you:

def dicts_from_file(file):
    dicts_from_file = []
    with open(file,'r') as inf:
        for line in inf:
            dicts_from_file.append(eval(line))
    return dicts_from_file

def get_setups(dicts):
    setups = []
    for dict in dicts:
        for key in dict:
            if key == "setup":
                setups.append(dict[key])
    return setups

print get_setups(dicts_from_file("data.txt"))

Answer 2

    f = open('data')
    for line in f:
        d = ast.literal_eval(line)[0]
        print d['setup']

for this code you need to put ',' after every line because ast.literal_eval(line) convert line into a tuple.

and if you do not have ',' after every dict then use this

f = open('data')
for line in f:
   d = ast.literal_eval(line)
   print d['setup']

Answer 3

You can try this if the line in your file is standard dict string.

def get_setup_from_file(file_name):
    result = []
    f = open(file_name, "r")
    for line in f.xreadlines():
        # or  line_dict = json.loads(line)
        line_dict = eval(line)  # if line end witch ',', try eval(line[0:-1])
        result.append(line_dict["setup"])
    return result

Wish this can help you.

Answer 4

if it is standard dict string, try this:

with open(file,'r') as file_input:
    for line in file_input:
        print eval(line).get("setup")