I am trying to parse JSON from Python. I am able to parse JSON properly if I am using single quote around json string but if I remove that single quote then it doesn't works for me -
#!/usr/bin/python
import json
# getting JSON string from a method which gives me like this
# so I need to wrap around this dict with single quote to deserialize the JSON
jsonStr = {"hello":"world"}
j = json.loads(`jsonStr`) #this doesnt work either?
shell_script = j['hello']
print shell_script
So my question is how to wrap that JSON string around single quote so that I am able to deserialize it properly?
The error that I get -
$ python jsontest.py
Traceback (most recent call last):
File "jsontest.py", line 7, in <module>
j = json.loads('jsonStr')
File "/usr/lib/python2.7/json/__init__.py", line 326, in loads
return _default_decoder.decode(s)
File "/usr/lib/python2.7/json/decoder.py", line 366, in decode
obj, end = self.raw_decode(s, idx=_w(s, 0).end())
File "/usr/lib/python2.7/json/decoder.py", line 384, in raw_decode
raise ValueError("No JSON object could be decoded")
ValueError: No JSON object could be decoded
I think you are confusing two different concepts here between dumps() and loads()
jsonStr = {"hello":"world"}
j = json.loads(json.dumps(jsonStr)) #this should work
shell_script = j['hello']
print shell_script
But yes, it's redundant since jsonStr is already an object. If you wanted to try loads() you need a valid json string as input, like such:
jsonStr = '{"hello":"world"}'
j = json.loads(jsonStr) #this should work
shell_script = j['hello']
print shell_script
jsonStr is a dictionary not a string. It's already "loaded".
You should be able to directly call
shell_script = jsonStr['hello']
print shell_script
Related
I have a string that I need to load into a dictionary. I'm trying to use json.loads() to do this, but it is failing because I need to replace single quotes with double quotes because by default the strings use single quotes to wrap property names and values, although in some cases the value is wrapped in double quotes because it contains an single quote.
Here is a reproduceable example using Python3.8
>>> import json
>>> example = "{'msg': \"I'm a string\"}"
>>> json.loads(example.replace("'", '"'))
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/usr/local/lib/python3.8/json/__init__.py", line 357, in loads
return _default_decoder.decode(s)
File "/usr/local/lib/python3.8/json/decoder.py", line 337, in decode
obj, end = self.raw_decode(s, idx=_w(s, 0).end())
File "/usr/local/lib/python3.8/json/decoder.py", line 353, in raw_decode
obj, end = self.scan_once(s, idx)
json.decoder.JSONDecodeError: Expecting ',' delimiter: line 1 column 12 (char 11)
Is there a better way to load a string into a dictionary? The json module seems to only work with double quotes and as that is not possible here (I have no control over the formatting of the strings), hence why I'm having to use the unreliable replace.
My desired result is to have a dictionary like this.
{'msg': "I'm a string"}
Use ast.literal_eval()Docs:
>>> import ast
>>> ast.literal_eval(example)
{'msg': "I'm a string"}
I am currently tring to work with import a json input that is accepted by Python through a commandline argument and I am trying to save the different values to JSON to a list. I am having issues with my code given below and have attached both the code and the error I get below. Any help much appreciated.
import sys
import json
def lookup1 ():
jsonData = json.loads(sys.argv[1])
print jsonData
jsonList = [jsonData['proxy'],jsonData['OS']]
print jsonList
lookup1()
The error is given below:
$ python dynamicMapper.py '{'proxy':1,'OS':2}'
Traceback (most recent call last):
File "dynamicMapper.py", line 9, in <module>
lookup1()
File "dynamicMapper.py", line 4, in lookup1
jsonData = json.loads(sys.argv[1])
File "/usr/lib/python2.7/json/__init__.py", line 338, in loads
return _default_decoder.decode(s)
File "/usr/lib/python2.7/json/decoder.py", line 366, in decode
obj, end = self.raw_decode(s, idx=_w(s, 0).end())
File "/usr/lib/python2.7/json/decoder.py", line 382, in raw_decode
obj, end = self.scan_once(s, idx)
ValueError: Expecting property name: line 1 column 2 (char 1)
The commadline argunet that I give is python dynamicMapper.py '{'proxy':1,'OS':2}'
I am not able to find out what is causing this error and if my approach is right.
The script is working fine, you just need to call it the right way:
python dynamicMapper.py '{"proxy":1,"OS":2}'
{u'OS': 2, u'proxy': 1}
[1, 2]
In JSON the strings are quoted with double quotes instead of single quotes. You also need to quote the string passed to script so that shell understands it being a single argument.
I am trying to parse some text files containing JSON objects in Python using the json.load() method. It's working for one set of them, but for this one it will not:
{
"mapinfolist":{
"mapinfo":[
{"sku":"00028-0059","price":"38.35","percent":"50","basepercent":"50","exact":0,"match":0,"roundup":0}
,{"sku":"77826-7230","price":"4.18","percent":"60","basepercent":"60","exact":1,"match":0,"roundup":0}
,{"sku":"77827-1310","price":"2.36","percent":"60","basepercent":"60","exact":1,"match":0,"roundup":0}
,{"sku":"77827-2020","price":"2.36","percent":"60","basepercent":"60","exact":1,"match":0,"roundup":0}
,{"sku":"77827-3360","price":"2.36","percent":"60","basepercent":"60","exact":1,"match":0,"roundup":0}
,{"sku":"77827-4060","price":"2.36","percent":"60","basepercent":"60","exact":1,"match":0,"roundup":0}
,{"sku":"77827-4510","price":"2.36","percent":"60","basepercent":"60","exact":1,"match":0,"roundup":0}
,{"sku":"77827-7230","price":"2.36","percent":"60","basepercent":"60","exact":1,"match":0,"roundup":0}
],
"count":2
}
}
It is in a file called 'map.txt' - I open it using open('map.txt') and then call json.load(). When I run my test program (test.py), the following error trace is generated:
Traceback (most recent call last):
File "test.py", line 28, in <module>
main()
File "test.py", line 23, in main
map_list = json.load(f1)
File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/json/__init__.py", line 268, in load
parse_constant=parse_constant, object_pairs_hook=object_pairs_hook, **kw)
File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/json/__init__.py", line 318, in loads
return _default_decoder.decode(s)
File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/json/decoder.py", line 343, in decode
obj, end = self.raw_decode(s, idx=_w(s, 0).end())
File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/json/decoder.py", line 361, in raw_decode
raise ValueError(errmsg("Expecting value", s, err.value)) from None
ValueError: Expecting value: line 1 column 1 (char 0)
The JSON object is valid - when I put it into https://www.jsoneditoronline.org/ it is parsed and displayed correctly, so I am having trouble identifying what could be stopping it from working when I try to do it in Python. Any advice would be much appreciated. Thanks!
EDIT: Here's my code.
import json
def main():
with open('map.txt') as f1:
map_list = json.load(f1)
Trying map_list = json.loads(f1.read()) also does not work and gives me an almost identical error trace.
EDIT - RESOLVED:
I just copied and pasted FROM map.txt into a new TextEdit file map2.txt and used the new file instead, and it works now. I copied directly from the old file and made no changes - the only difference is that it is a different file. I can't make heads or tails of why that would be - any ideas? I would like to understand what may have happened so I can avoid the problem in the future.
Does the following solution work for you?
import json
f = open("map.txt")
map = json.loads(f.read())
Python Docs
maybe try to read all the file to string and then use json.loads
def yourfunc():
file = open('map.txt')
json_string = file.read()
map = json.loads(json_string)
This question already has answers here:
How can I parse (read) and use JSON?
(5 answers)
Closed last month.
A simple looking, easy statement is throwing some errors in my face.
I have a JSON file called strings.json like this:
"strings": [{"-name": "city", "#text": "City"}, {"-name": "phone", "#text": "Phone"}, ...,
{"-name": "address", "#text": "Address"}]
I want to read the JSON file, just that for now. I have these statements which I found out, but it's not working:
import json
from pprint import pprint
with open('strings.json') as json_data:
d = json.loads(json_data)
json_data.close()
pprint(d)
The error displayed on the console was this:
Traceback (most recent call last):
File "/home/.../android/values/manipulate_json.py", line 5, in <module>
d = json.loads(json_data)
File "/usr/lib/python2.7/json/__init__.py", line 326, in loads
return _default_decoder.decode(s)
File "/usr/lib/python2.7/json/decoder.py", line 366, in decode
obj, end = self.raw_decode(s, idx=_w(s, 0).end())
TypeError: expected string or buffer
[Finished in 0.1s with exit code 1]
If I use json.load instead of json.loads, I get this error:
Traceback (most recent call last):
File "/home/.../android/values/manipulate_json.py", line 5, in <module>
d = json.load(json_data)
File "/usr/lib/python2.7/json/__init__.py", line 278, in load
**kw)
File "/usr/lib/python2.7/json/__init__.py", line 326, in loads
return _default_decoder.decode(s)
File "/usr/lib/python2.7/json/decoder.py", line 369, in decode
raise ValueError(errmsg("Extra data", s, end, len(s)))
ValueError: Extra data: line 829 column 1 - line 829 column 2 (char 18476 - 18477)
[Finished in 0.1s with exit code 1]
The json.load() method (without "s" in "load") can read a file directly:
import json
with open('strings.json') as f:
d = json.load(f)
print(d)
You were using the json.loads() method, which is used for string arguments only.
The error you get with json.loads is a totally different problem. In that case, there is some invalid JSON content in that file. For that, I would recommend running the file through a JSON validator.
There are also solutions for fixing JSON like for example How do I automatically fix an invalid JSON string?.
Here is a copy of code which works fine for me,
import json
with open("test.json") as json_file:
json_data = json.load(json_file)
print(json_data)
with the data
{
"a": [1,3,"asdf",true],
"b": {
"Hello": "world"
}
}
You may want to wrap your json.load line with a try catch, because invalid JSON will cause a stacktrace error message.
The problem is using the with statement:
with open('strings.json') as json_data:
d = json.load(json_data)
pprint(d)
The file is going to be implicitly closed already. There is no need to call json_data.close() again.
In Python 3, we can use the below method.
Read from a file and convert to JSON
import json
from pprint import pprint
# Considering "json_list.json" is a JSON file
with open('json_list.json') as fd:
json_data = json.load(fd)
pprint(json_data)
The with statement automatically closes the opened file descriptor.
String to JSON
import json
from pprint import pprint
json_data = json.loads('{"name" : "myName", "age":24}')
pprint(json_data)
You can use the Pandas library to read the JSON file.
import pandas as pd
df = pd.read_json('strings.json', lines=True)
print(df)
To add on this, today you are able to use pandas to
import JSON: pandas.read_json
You may want to do a careful use of the orient parameter.
def read_JSON():
with open("FILE PATH", "r") as i:
JSON_data = i.read()
print(JSON_data)
I'm currently trying to parse through a text file containing a number of Facebook chat fragments. The fragments are stored as below:-
{"t":"msg","c":"p_100002239013747","s":14,"ms":[{"msg":{"text":"2what is the best restauran
t in hong kong? ","time":1303115825598,"clientTime":1303115824391,"msgID":"1862585188"},"from":10000
2239013747,"to":635527479,"from_name":"David Robinson","from_first_name":"David","from_gender":1,"to_name":"Jason Yeung","to_first_name":"Jason","to_gender":2,"type":"msg"}]}
I've tried a number of ways to parse / open the JSON file but to no avail. Here is what I've tried thusfar:-
import json
data = []
with open("C:\\Users\\Me\\Desktop\\facebookchat.txt", 'r') as json_string:
for line in json_string:
data.append(json.loads(line))
error:
Traceback (most recent call last):
File "C:/Users/Amy/Desktop/facebookparser.py", line 6, in <module>
data.append(json.loads(line))
File "C:\Program Files\Python27\lib\json\__init__.py", line 326, in loads
return _default_decoder.decode(s)
File "C:\Program Files\Python27\lib\json\decoder.py", line 366, in decode
obj, end = self.raw_decode(s, idx=_w(s, 0).end())
File "C:\Program Files\Python27\lib\json\decoder.py", line 382, in raw_decode
obj, end = self.scan_once(s, idx)
ValueError: Invalid control character at: line 1 column 91 (char 91)
and also:
import json
with open("C:\\Users\\Me\\Desktop\\facebookchat.txt", 'r') as json_file:
data = json.load(json_file)
... but I get exactly the same error as above.
Any suggestions? I've searched previous posts on here and tried the alternative solutions but to no avail. I'm aware I need to treat it as a dictionary file with for example, 'time' being a key and '1303115825598' being the respective time value but if I can't even process the json file into memory, there's no way I can parse it.
Where am I going wrong? Thanks
Your data contains newlines where JSON would not allow these. You'll have to stitch the lines back together again:
data = []
with open("C:\\Users\\Me\\Desktop\\facebookchat.txt", 'r') as json_string:
partial = ''
for line in json_string:
partial += line.rstrip('\n')
try:
data.append(json.loads(partial))
partial = ''
except ValueError:
continue # Not yet a complete JSON value
The code collects lines into partial, but minus the newline, and tries to decode the JSON. If that succeeds, partial is set to the empty string again to process the next entry. If it fails, we loop to the next line to append, until there is a complete JSON value to decode.