This might seem stupid to you but I noticed something and I just dont udnerstand it.

h = '[{"b": [2, 4], "c": 3.0, "a": "A"}]'
json.loads(h)

This will work, but this:

h = '"[{"b": [2, 4], "c": 3.0, "a": "A"}]"'
json.loads(h)

Will raise an exepction JSONDecodeError: Extra data: line 1 column 5 (char 4)

h = '"hey"'
json.loads(h)

This will also work.

Can someone please explain to me the differences between ''','" and '?

CodePudding user response：

Consider the middle example, from the perspective of individual strings (within your strin), you are asking json to load. By adding the first ", you are shifing all strings by one:

h = '"[{"b": [2, 4], "c": 3.0, "a": "A"}]"'
      --   ----------   -------   --
Strings surrounded by quotes

So when you first reach a non string b, json has no idea what to do with it. If you want to treat the entire content as a string, you need to escape the quotes \\". So it would look like this:

h = '"[{\\"b\\": [2, 4], \\"c\\": 3.0, \\"a\\": \\"A\\"}]"'

CodePudding user response：

It's saying that the character number 4 is not recognized.

That's normal, the decoder goes like that

char 0 " --> this is a string start
char 1 [ --> this is inside the string
char 2 { --> this is inside the string
char 3 " --> this is the end of the string
char 4 b --> this has nothing to do here, stop execution and raise error

CodePudding user response：

Here

h = '"[{"b": [2, 4], "c": 3.0, "a": "A"}]"'

you are attempting to use " for 2 different meanings: as string delimiter (1st and last) and literal " (all others). In such case way of escaping is required to tell that " is literally " consider what would be effect of following dumps

import json
text = 'this text does contain "quotation" marks'
print(json.dumps(text))

gives output

"this text does contain \"quotation\" marks"

Note \ pointing literal ".