Borislav Hadzhiev
Wed Apr 20 2022·2 min read
Photo by Raychan
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.
# ⛔️ NameError: name 'json' is not defined json_str = json.dumps({'name': 'Alice', 'age': 30})
To solve the error, we have to import the json module.
# ✅ import json first import json json_str = json.dumps({'name': 'Alice', 'age': 29}) print(json_str) # 👉️ '{"name": "Alice", "age": 29}' print(type(json_str)) # 👉️ <class 'str'> native_python_obj = json.loads(json_str) print(native_python_obj) # 👉️ {'name': 'Alice', 'age': 29} print(type(native_python_obj)) # 👉️ <class 'dict'>
Even though the json
module is in the Python standard library, we still have
to import it before using it.
j
when importing json
because module names are case-sensitive.Also, make sure you haven't imported json
in a nested scope, e.g. a function.
Import the module at the top level to be able to use it throughout your code.
An alternative to importing the entire json
module is to import only the
functions and constants that your code uses.
from json import dumps, loads json_str = dumps({'name': 'Alice', 'age': 29}) print(json_str) # 👉️ '{"name": "Alice", "age": 29}' print(type(json_str)) # 👉️ <class 'str'> native_python_obj = loads(json_str) print(native_python_obj) # 👉️ {'name': 'Alice', 'age': 29} print(type(native_python_obj)) # 👉️ <class 'dict'>
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.
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.