The package for json_lines in pip in json-lines. Hence you could install it as:

$ pip install json-lines

It may be appropriate to use an isolated python environment for your particular project if you want to use particular conda libraries but without the whole package. In this instance, you would be able to use virtualenv. This will allow you to create an isolated python environment.

$ pip3 install virtualenv

You can call virtualenv to create a virtual python environment with the working name e.g. myvenv.

$ virtualenv myvenv

From here, you can set your terminal to use this python version. If you are on *nix:

$ which python
/usr/bin/python
$ source myvenv/bin/activate
(myvenv)$ which python
/.../myvenv/bin/python

Note: I do not have a definitive answer but will offer a series of steps you can try:

The first thing is see if you can import json from the usual python interpreter:

import json
print(json.__file__) #this would be important to know if it works

If that does work (as well as commenting what json.__file__ is) you would then want to try to use pip from the interpreter.

If you can't import json normally:

This is not surprising, I did not expect pip to be looking in a non-standard place for modules. You will want to figure out where the json package should be located on your computer, you can do this by importing another module from the standard library and looking at it's __file__:

>>> import fractions
>>> fractions.__file__
'/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/fractions.py'

This will obviously be different for you but I'd expect there to be a json folder in the same folder as fractions.py

if you can't import fractions or queue or datetime etc.

If you can't import anything from the standard library you will probably want to just reinstall python.

If the json folder is there and contains an __init__.py

Use the rename function of your file browser to make sure there are no weird special characters, but other then that I'm not sure, if you can import fractions.py but not a package from the same folder that would imply there is something very wrong with the import mechanics of your python version.

If the json folder is not with the rest of the standard library

It is possible that your python distribution has a different structure then I'd expect, it at least can't hurt to take a look for it.

You can search for the json folder amongst your various python files using the find command, not really sure how it works but just another thing to try. If you do find it with the __init__.py, encode.py, decode.py, scanner.py, and tool.py (at least those are the ones in my version) you'll probably want to figure out how it got there, but maybe just move it to the same folder as the rest of the standard library.

If you can't find the json package or you find it and it is corrupted

Well then you will need to replace it! Don't worry, this isn't too hard, just grab a source release of python from the site and extract the json package from it, once it is uncompressed the json folder should be in the Lib folder. Simply copy/move it to the rest of the standard library and you should be good to go!

I hope this helps you debug what is going on, This covers all the scenarios I could imagine happening and I would be interested in which one fixed your issue (or what you were able to figure out so I can come up with more options)

import jsonlines

with jsonlines.open('example.jsonl', 'r') as jsonl_f:
     lst = [obj for obj in jsonl_f]

The jsonl_f is the reader and can be used directly. It contains the lines in the json file.