How to check if a string is valid JSON in Python?

How to check if a string is valid JSON in Python?

To check if a string is valid JSON in Python, you can use a try-except block along with the json.loads() function from the json module. Here's a simple example:

import json def is_valid_json(json_str): try: json.loads(json_str) return True except ValueError: return False # Test with valid JSON valid_json_str = '{"key": "value", "array": [1, 2, 3]}' print(is_valid_json(valid_json_str)) # Output: True # Test with invalid JSON invalid_json_str = '{"key": "value", "missing_quote: "value"}' print(is_valid_json(invalid_json_str)) # Output: False

In the is_valid_json function:

  1. We try to load the input json_str using json.loads(). If the string is valid JSON, this operation will succeed, and the function will return True.

  2. If the string is not valid JSON, json.loads() will raise a ValueError exception, which we catch in the except block, and the function will return False.

By using this method, you can easily check if a string is valid JSON in Python.

Examples

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    • Code:
      import json def is_valid_json(json_str): try: json.loads(json_str) return True except ValueError: return False # Example usage: json_string = '{"key": "value"}' print(is_valid_json(json_string)) # Output: True

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    • Code:
      import json def is_json_string(s): try: json.loads(s) except ValueError: return False return True # Example usage: json_str = '{"key": "value"}' print(is_json_string(json_str)) # Output: True

  3. Search Query: "Python JSON validation function"

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    • Code:
      import jsonschema def validate_json(json_str): try: json.loads(json_str) return True except ValueError: return False # Example usage: json_string = '{"key": "value"}' print(validate_json(json_string)) # Output: True

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    • Code:
      from jsonschema import validate def validate_json_schema(json_str, schema): try: validate(instance=json.loads(json_str), schema=schema) return True except Exception as e: return False # Example usage: json_string = '{"key": "value"}' sample_schema = { "type": "object", "properties": { "key": {"type": "string"} }, "required": ["key"] } print(validate_json_schema(json_string, sample_schema)) # Output: True

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    • Code:
      import json def validate_json_string(json_str): try: json.loads(json_str) return True except ValueError: return False # Example usage within a script: if __name__ == "__main__": input_json = input("Enter a JSON string: ") if validate_json_string(input_json): print("Valid JSON") else: print("Invalid JSON")

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    • Code:
      import jsonschema def validate_json(json_str, schema): try: jsonschema.validate(json.loads(json_str), schema) return True except jsonschema.ValidationError: return False # Example usage: json_string = '{"key": "value"}' sample_schema = { "type": "object", "properties": { "key": {"type": "string"} }, "required": ["key"] } print(validate_json(json_string, sample_schema)) # Output: True

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    • Description: Users using this query are likely searching for Python code snippets that can quickly verify if a given string conforms to the JSON format.
    • Code:
      import json def is_valid_json_format(json_str): try: json.loads(json_str) return True except json.JSONDecodeError: return False # Example usage: json_string = '{"key": "value"}' print(is_valid_json_format(json_string)) # Output: True

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    • Code:
      import json def is_json_string(s): try: json.loads(s) except (json.JSONDecodeError, TypeError): return False return True # Example usage: json_str = '{"key": "value"}' print(is_json_string(json_str)) # Output: True

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    • Code:
      import json def is_json_object(s): try: obj = json.loads(s) return isinstance(obj, dict) except ValueError: return False # Example usage: json_str = '{"key": "value"}' print(is_json_object(json_str)) # Output: True

  10. Search Query: "How to validate JSON string using Python"

    • Description: This query suggests users are seeking methods or functions in Python to validate JSON strings effectively.
    • Code:
      import json def validate_json(json_str): try: json.loads(json_str) return True except ValueError: return False # Example usage: json_string = '{"key": "value"}' print(validate_json(json_string)) # Output: True

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