Python json loads none

Python json loads none

Last updated: Feb 18, 2023
Reading time · 2 min

# Convert JSON NULL values to None using Python

Use the json.loads() method to convert JSON NULL values to None in Python. The json.loads method parses a JSON string into a native Python object.

Conversely, the json.dumps method converts a Python object to a JSON formatted string.

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import json my_json = r'' my_dict = json.loads(my_json) print(type(my_dict)) # 👉️ print(my_dict) # 👉️ 

The example shows how to convert null values to None using the json.loads() method.

# Convert JSON NULL values to Python None values

The json.loads method parses a JSON string into a native Python object.

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import json json_str = r'' my_dict = json.loads(json_str) print(type(my_dict)) # 👉️ 

The process of converting a JSON string to a native Python object is called deserialization.

# Convert Python None values to JSON NULL values

You can use the json.dumps method to convert a Python object to a JSON formatted string.

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import json my_json = r'' # ✅ convert NULL values to None (JSON string to Python object) my_dict = json.loads(my_json) print(type(my_dict)) # 👉️ print(my_dict) # 👉️ # ✅ convert None to null (Python object to JSON string) my_json_again = json.dumps(my_dict) print(my_json_again) # 👉️ '' 

The process of converting a native Python object to a JSON string is called serialization.

You can also have None keys in Python objects, but it should generally be avoided.

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import json my_dict = 'name': 'Bobby', None: None> print(my_dict) # 👉️ my_json = json.dumps(my_dict) print(my_json) # 👉️ '' my_dict_again = json.loads(my_json) print(my_dict_again) # 👉️ 

We started with a Python object that has a None key and a None value.

When we converted the object to JSON, both the key and the value got converted to null .

When we parsed the JSON string into a Python object, the value got converted to None , but the key is still the string null .

This is because JSON keys must be of type string . If we pass a key of any other type to the json.dumps() method, the key automatically gets converted to a string.

Once the key is converted to a string, parsing the JSON string will return a string key in the Python object.

# Additional Resources

You can learn more about the related topics by checking out the following tutorials:

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Python json loads none

Last updated: Feb 1, 2023
Reading time · 7 min

# Table of Contents

# NameError: name ‘null’ is not defined in Python

The Python «NameError: name ‘null’ is not defined» occurs when we use null instead of None in Python or we forget to parse JSON data into native Python objects.

To solve the error, replace any occurrences of null with None in your code.

Here is an example of how the error occurs.

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# ⛔️ NameError: name 'null' is not defined val = null print(val) 

# Use None instead of null in Python

To solve the error, we have to use None instead of null in Python.

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val = None print(val) # 👉️ None 

The None object is used to represent the absence of a value.

# Parsing a JSON string into a native Python object

If you have a JSON string, you have to parse it to a native Python object before accessing specific properties.

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import json json_str = json.dumps('name': None>) print(json_str) # 👉️ '' print(type(json_str)) # 👉️ # ✅ Parse JSON string to native Python object native_python_obj = json.loads(json_str) print(native_python_obj) # 👉️ print(type(native_python_obj)) # 👉️ print(native_python_obj['name']) # 👉️ None 

We used the json.dumps method to serialize a Python object to a JSON formatted string.

Notice that None becomes null when converted to a JSON string.

# Converting a Python object to a JSON string

Conversely, you can use the json.loads method to deserialize a JSON string to a native Python object.

When we parse a JSON string into a Python object, null values become None .

If you have a JSON string in your code, you can use the json.loads() method to convert it to a Python object.

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import json json_str = r'''''' native_python_obj = json.loads(json_str) print(native_python_obj) # 👉️ 

Notice that all null values become None after parsing the JSON string into native Python.

# Declaring a null variable in your code

Alternatively, you can declare a null variable and assign it a value of None .

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null = None my_dict = "name": null, "age": null> print(my_dict) 

However, note that this is a hacky solution and might be confusing to readers of your code.

# Parsing the response from the requests module

If you use the requests module to make HTTP requests, you can call the json() method on the response object to parse the JSON string into a native Python object.

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import requests def make_request(): res = requests.get('https://reqres.in/api/users') print(type(res)) # 👉️ # ✅ Parse JSON to native Python object parsed = res.json() print(parsed) print(type(parsed)) # 👉️ make_request() 

The res variable is a Response object that allows us to access information from the HTTP response.

We can call the json() method on the Response object to parse the JSON string into a native Python object which would convert any null values to their Python equivalent of None .

# NameError: name ‘json’ is not defined in Python

The Python «NameError: name ‘json’ is not defined» occurs when we use the json module without importing it first.

To solve the error, import the json module before using it — import json .

Here is an example of how the error occurs.

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# ⛔️ NameError: name 'json' is not defined json_str = json.dumps('name': 'Bobby Hadz', 'age': 30>) 

To solve the error, we have to import the json module.

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# ✅ import json first import json json_str = json.dumps('name': 'Bobby Hadz', 'age': 29>) print(json_str) # 👉️ '' print(type(json_str)) # 👉️ native_python_obj = json.loads(json_str) print(native_python_obj) # 👉️ print(type(native_python_obj)) # 👉️ 

Even though the json module is in the Python standard library, we still have to import it before using it.

Make sure you haven’t used a capital letter j when importing json because module names are case-sensitive.

# Don’t import the json module in a nested scope

Also, make sure you haven’t imported json in a nested scope, e.g. a function.

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def get_json(): import json json_str = json.dumps('name': 'Bobby Hadz', 'age': 29>) print(json_str) # ⛔️ NameError: name 'json' is not defined json_str = json.dumps('name': 'Bobby Hadz', 'age': 29>) 

We imported the json module in a function, so we aren’t able to use it outside of the function.

Import the module at the top level to be able to use it throughout your code.

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# ✅ moved import to the top of the file import json def get_json(): json_str = json.dumps('name': 'Bobby Hadz', 'age': 29>) print(json_str) json_str = json.dumps('name': 'Bobby Hadz', 'age': 29>) 

The import statement should be at the top of your file, before any lines that make use of the json module.

# Make sure to not import the json module in a try/except statement

You also should be importing the json module in a try/except statement.

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import json try: # 👉️ code here could raise an error json_str = json.dumps('name': 'Bobby Hadz', 'age': 29>) print(json_str) except ImportError: json_str = json.dumps('name': 'Bobby Hadz', 'age': 29>) json_str = json.dumps('name': 'Bobby Hadz', 'age': 29>) 

The code sample works, however, if the code in the try statement raises an error, the json module won’t get imported successfully.

This would cause the error because we are trying to access properties on the json module in the outer scope and the except block.

# Importing specific functions from the json module

An alternative to importing the entire json module is to import only the functions and constants that your code uses.

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from json import dumps, loads json_str = dumps('name': 'Bobby Hadz', 'age': 29>) print(json_str) # 👉️ '' print(type(json_str)) # 👉️ native_python_obj = loads(json_str) print(native_python_obj) # 👉️ print(type(native_python_obj)) # 👉️ 

The example shows how to import only the dumps and loads functions from the json module.

Instead of accessing the members on the module, e.g. json.loads , we now access them directly.

You should pick whichever approach makes your code easier to read.

For example, when we use an import such as import json , it is much harder to see which functions from the json module are being used in the file.

Conversely, when we import specific functions, it is much easier to see which functions from the json module are being used.

However, you will most likely be using only 2 functions from the json module — json.dumps() and json.loads() .

The json.dumps function is used to serialize a Python object to a JSON formatted string.

Conversely, you can use the json.loads function to deserialize a JSON string to a native Python object.

You can view all of the functions the json module provides by visiting the official docs.

# NameError: name ‘true’ or ‘false’ is not defined in Python

The Python «NameError: name ‘true’ is not defined» occurs when we misspell the keyword True .

To solve the error, make sure to capitalize the first letter of the keyword — True .

Here is an example of how the error occurs.

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# ⛔️ NameError: name 'true' is not defined. Did you mean: 'True'? t = true print(t) 

You might also get the error when you forget to capitalize the letter F in False .

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# ⛔️ NameError: name 'false' is not defined. Did you mean: 'False'? f = false print(f) 

# Use True and False in Python (capital first letter)

To solve the error, we have to use a capital T when spelling the True keyword.

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t = True print(t) # True 

Names of variables, functions, classes and keywords are case-sensitive in Python.

The only other available boolean value is False (capital F ).

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t = True print(t) # 👉️ True f = False print(f) # 👉️ False 

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