My guess is that you're expecting to see more structure in the JSON you are getting, like seeing a pair of curly braces or square brackets?. But curlies represent a dictionary (key/value pairs), and square brackets represent an array or list. What you are encoding as JSON is neither of those things.

page.extractText returns text from the PDF being read as a single Python string value. The JSON encoding of a Python string value is the text of that string within a pair of double quotes. So the JSON you're getting will be of the form:

"<text from pdf document>"

It doesn't matter what's in the PDF. Whatever text you get back from page.extractText will always be a single Python string. What you get when you encode that string as JSON will always be that same text, with double quotes before and after it.

Here's a little code to illustrate this:

import json
s1 = "This is a Python string.  A Python string encoded as JSON is the text of that string surrounded by double quotes"
print(s1)
print(json.dumps(s1))

Result:

This is a Python string.  A Python string encoded as JSON is the text of that string surrounded by double quotes
"This is a Python string.  A Python string encoded as JSON is the text of that string surrounded by double quotes"

Not so pretty, but this would get the job done, I think. You would get a dictionary which then gets printed by the json parser in a nice, pretty format.

import json    

def get_data(page_content):
    _dict = {}
    page_content_list = page_content.splitlines()
    for line in page_content_list:
        if ':' not in line:
            continue
        key, value = line.split(':')
        _dict[key.strip()] = value.strip()
    return _dict

page_data = get_data(page_content)
json_data = json.dumps(page_data, indent=4)
print(json_data)

or, instead of those last 3 lines, just do this:

print(json.dumps(get_data(page_content), indent=4))