How to replace None value with "None" string value

Question

I have a text file that I am trying to write to a JSON file. Some of the values are returned as None, True or False. I need to replace None with "None" (string), True with "True" and False with "False"

I tried adding the line

data=data.replace(None,"None")

However, I get an error

Traceback (most recent call last):
  File "parse_get_drivers.py", line 17, in <module>
    data=data.replace(None,"None")
TypeError: replace() argument 1 must be str, not None

Here is my script

import json
import re
from pprint import pprint
import pandas as pd

inHandler = open('get_drivers.txt', 'r')
outHandler = open('drivers.json', 'w')
data = ''


for line in inHandler.readlines():
    print('src:' + line)
    line = line.replace("}]},","}]},\r")
    data += line
    print('replace:' + line)
    data=data.replace("'", '"')
    data=data.replace(None,"None")

outHandler.write(data)

inHandler.close()
outHandler.close()

The required result is to replace None, True and False values with "None", "True" and "False".

This makes no sense. Use json.loads, and especially if you are not loading the JSON, True/False/None should already be string values. — moltarze
– moltarze, Commented Mar 22, 2019 at 18:40

blhsing · Accepted Answer · 2019-03-22 18:57:34Z

1

You should parse the input as JSON instead of parsing it line by line as separate strings, so that you can recursively traverse the data structure to replace None (or in JSON's terms, null) with "None":

def replace(data, search, replacement, parent=None, index=None):
    if data == search:
        parent[index] = replacement
    elif isinstance(data, (list, dict)):
        for index, item in enumerate(data) if isinstance(data, list) else data.items():
            replace(item, search, replacement, parent=data, index=index)

so that:

import json
d = json.loads('{"a": 1, "b": [1, null], "c": {"d": null}}')
print(d)
replace(d, None, 'None')
print(d)
print(json.dumps(d))

outputs:

{'a': 1, 'b': [1, None], 'c': {'d': None}}
{'a': 1, 'b': [1, 'None'], 'c': {'d': 'None'}}
{"a": 1, "b": [1, "None"], "c": {"d": "None"}}

edited Mar 22, 2019 at 18:57

answered Mar 22, 2019 at 18:52

blhsing

109k9 gold badges88 silver badges132 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

How to replace None value with "None" string value

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related