Converting “true” (JSON) to Python equivalent “True”

Question

The Train status API I use recently added two additional key value pairs (has_arrived, has_departed) in the JSON object, which caused my script to crash.

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Answer 1

{ "value": False } or { "key": false } is not a valid json https://jsonlint.com/

Answer 2

It is possible to utilize Python's boolean value for int, str, list etc.

For example:

bool(1)     # True
bool(0)     # False

bool("a")   # True
bool("")    # False

bool([1])   # True
bool([])    # False

In Json file, you can set

"has_arrived": 0,

Then in your Python code

if data["has_arrived"]:
    arrived()
else:
    not_arrived()

The issue here is not to confuse 0 indicated for False and 0 for its value.

Answer 3

json.loads cant parse the pythons boolean type (False, True). Json wants to have small letters false, true

my solution:

python_json_string.replace(": True,", ": true,").replace(": False,", ": false,")

Answer 4

Even though Python's object declaration syntax is very similar to Json syntax, they're distinct and incompatible. As well as the True/true issue, there are other problems (eg Json and Python handle dates very differently, and python allows single quotes and comments while Json does not).

Instead of trying to treat them as the same thing, the solution is to convert from one to the other as needed.

Python's json library can be used to parse (read) the Json in a string and convert it into a python object...

data_from_api = '{"response_code": 200, ...}'  # data_from_api should be a string containing your json
info = json.loads(data_from_api)
# info is now a python dictionary (or list as appropriate) representing your Json

You can convert python objects to json too...

info_as_json = json.dumps(info)

Example:

# Import the json library
import json

# Get the Json data from the question into a variable...
data_from_api = """{
"response_code": 200,
  "train_number": "12229",
  "position": "at Source",
  "route": [
    {
      "no": 1, "has_arrived": false, "has_departed": false,
      "scharr": "Source",
      "scharr_date": "15 Nov 2015", "actarr_date": "15 Nov 2015",
      "station": "LKO", "actdep": "22:15", "schdep": "22:15",
      "actarr": "00:00", "distance": "0", "day": 0
    },
    {
      "actdep": "23:40", "scharr": "23:38", "schdep": "23:40",
      "actarr": "23:38", "no": 2, "has_departed": false,
      "scharr_date": "15 Nov 2015", "has_arrived": false,
      "station": "HRI", "distance": "101",
      "actarr_date": "15 Nov 2015", "day": 0
    }
  ]
}"""

# Convert that data into a python object...
info = json.loads(data_from_api)
print(info)

And a second example showing how the True/true conversion happens. Note also the changes to quotation, and how the comment is stripped...

info = {'foo': True,  # Some insightful comment here
        'bar': 'Some string'}

# Print a condensed representation of the object
print(json.dumps(info))

> {"bar": "Some string", "foo": true}

# Or print a formatted version which is more human readable but uses more bytes
print(json.dumps(info, indent=2))

> {
>   "bar": "Some string",
>   "foo": true
> }

Answer 5

You can also do a cast to boolean with the value. For example, assuming that your data is called "json_data":

value = json_data.get('route')[0].get('has_arrived') # this will pull "false" into *value

boolean_value = bool(value == 'true') # resulting in False being loaded into *boolean_value

It's kind of hackey, but it works.

Answer 6

Instead of doing eval on the answer, use the json module.