TypeError: string indices must be integers while parsing JSON using Python?

Question

I am confuse now why I am not able to parse this JSON string. Similar code works fine on other JSON string but not on this one - I am trying to parse JSON String and extract script from the JSON.

Below is my code.

for step in steps:     step_path = '/example/v1' +'/'+step      data, stat = zk.get(step_path)     jsonStr = data.decode("utf-8")     print(jsonStr)     j = json.loads(json.dumps(jsonStr))     print(j)     shell_script = j['script']     print(shell_script) 

So the first print(jsonStr) will print out something like this -

{"script":"#!/bin/bash\necho Hello world1\n"} 

And the second print(j) will print out something like this -

{"script":"#!/bin/bash\necho Hello world1\n"} 

And then the third print doesn't gets printed out and it gives this error -

Traceback (most recent call last):   File "test5.py", line 33, in <module>     shell_script = j['script'] TypeError: string indices must be integers 

So I am wondering what wrong I am doing here?

I have used same above code to parse the JSON and it works fine..

Answer 1

The problem is that jsonStr is a string that encodes some object in JSON, not the actual object.

You obviously knew it was a string, because you called it jsonStr. And it's proven by the fact that this line works:

jsonStr = data.decode("utf-8") 

So, jsonStr is a string. Calling json.dumps on a string is perfectly legal. It doesn't matter whether that string was the JSON encoding of some object, or your last name; you can encode that string in JSON. And then you can decode that string, getting back the original string.

So, this:

j = json.loads(json.dumps(jsonStr)) 

… is going to give you back the exact same string as jsonStr in j. Which you still haven't decoded to the original object.

To do that, just don't do the extra encode:

j = json.loads(jsonStr) 

If that isn't clear, try playing with it an interactive terminal:

>>> obj = ['abc', {'a': 1, 'b': 2}] >>> type(obj) list >>> obj[1]['b'] 2 >>> j = json.dumps(obj) >>> type(j) str >>> j[1]['b'] TypeError: string indices must be integers >>> jj = json.dumps(j) >>> type(jj) str >>> j '["abc", {"a": 1, "b": 2}]' >>> jj '"[\\"abc\\", {\\"a\\": 1, \\"b\\": 2}]"' >>> json.loads(j) ['abc', {'a': 1, 'b': 2}] >>> json.loads(j) == obj True >>> json.loads(jj) '["abc", {"a": 1, "b": 2}]' >>> json.loads(jj) == j True >>> json.loads(jj) == obj False 

Answer 2

Try replacing j = json.loads(json.dumps(jsonStr)) with j = json.loads(jsonStr).