python之将float字符串转换为json中的float

我有一个包含以下数据的 json(test.json) 文件。我有大约 10000 条记录。我需要将 value 从字符串转换为浮点写入新文件 (test1.json)。我如何从 Python 执行此操作？

{ 
    "name":"test001", 
    "cat":"test", 
    "loc":"x loc", 
    "ings":[ 
        { 
            "name":"rrrrrr", 
            "value":"13.0" 
        }, 
        { 
            "name":"hhhh", 
            "value":"18.0" 
        } 
    ], 
    "nums":[ 
        { 
            "name":"kkkk", 
            "value":"82.05" 
        }, 
        { 
            "name":"uuuuu", 
            "value":"53.55" 
        } 
    ] 
}, 
{ 
    "name":"test002", 
    "cat":"test1", 
    "loc":"y loc", 
    "ings":[ 
        { 
            "name":"trtrtr", 
            "value":"11.0" 
        }, 
        { 
            "name":"wewew", 
            "value":"19.0" 
        } 
    ], 
    "nums":[ 
        { 
            "name":"iuyt", 
            "value":"122.05" 
        }, 
        { 
            "name":"oiui", 
            "value":"15.5" 
        } 
    ] 
} 

生成的 json 文件(test1.json)应该如下所示...

{ 
    "name":"test001", 
    "cat":"test", 
    "loc":"x loc", 
    "ings":[ 
        { 
            "name":"rrrrrr", 
            "value":13.0 
        }, 
        { 
            "name":"hhhh", 
            "value":18.0 
        } 
    ], 
    "nums":[ 
        { 
            "name":"kkkk", 
            "value":82.05 
        }, 
        { 
            "name":"uuuuu", 
            "value":53.55 
        } 
    ] 
}, 
{ 
    "name":"test002", 
    "cat":"test1", 
    "loc":"y loc", 
    "ings":[ 
        { 
            "name":"trtrtr", 
            "value":11.0 
        }, 
        { 
            "name":"wewew", 
            "value":19.0 
        } 
    ], 
    "nums":[ 
        { 
            "name":"iuyt", 
            "value":122.05 
        }, 
        { 
            "name":"oiui", 
            "value":15.5 
        } 
    ] 
} 

请您参考如下方法:

您可以为 json.loads 提供一个 object_hook允许您修改在 json 中找到的任何对象(字典)的方法:

import json 
 
json_data = """ 
[{ 
    "name":"test001", 
    "cat":"test", 
    "loc":"x loc", 
    "ings":[ 
        { 
            "name":"rrrrrr", 
            "value":"13.0" 
        }, 
        { 
            "name":"hhhh", 
            "value":"18.0" 
        } 
    ], 
    "nums":[ 
        { 
            "name":"kkkk", 
            "value":"82.05" 
        }, 
        { 
            "name":"uuuuu", 
            "value":"53.55" 
        } 
    ] 
}, 
{ 
    "name":"test002", 
    "cat":"test1", 
    "loc":"y loc", 
    "ings":[ 
        { 
            "name":"trtrtr", 
            "value":"11.0" 
        }, 
        { 
            "name":"wewew", 
            "value":"19.0" 
        } 
    ], 
    "nums":[ 
        { 
            "name":"iuyt", 
            "value":"122.05" 
        }, 
        { 
            "name":"oiui", 
            "value":"15.5" 
        } 
    ] 
}] 
""" 
 
def as_float(obj): 
    """Checks each dict passed to this function if it contains the key "value" 
    Args: 
        obj (dict): The object to decode 
 
    Returns: 
        dict: The new dictionary with changes if necessary 
    """ 
    if "value" in obj: 
        obj["value"] = float(obj["value"]) 
    return obj 
 
 
if __name__ == '__main__': 
    l = json.loads(json_data, object_hook=as_float) 
    print (json.dumps(l, indent=4)) 

这会产生您想要的结果:

[ 
    { 
        "loc": "x loc", 
        "ings": [ 
            { 
                "name": "rrrrrr", 
                "value": 13.0 
            }, 
            { 
                "name": "hhhh", 
                "value": 18.0 
            } 
        ], 
        "name": "test001", 
        "nums": [ 
            { 
                "name": "kkkk", 
                "value": 82.05 
            }, 
            { 
                "name": "uuuuu", 
                "value": 53.55 
            } 
        ], 
        "cat": "test" 
    }, 
    { 
        "loc": "y loc", 
        "ings": [ 
            { 
                "name": "trtrtr", 
                "value": 11.0 
            }, 
            { 
                "name": "wewew", 
                "value": 19.0 
            } 
        ], 
        "name": "test002", 
        "nums": [ 
            { 
                "name": "iuyt", 
                "value": 122.05 
            }, 
            { 
                "name": "oiui", 
                "value": 15.5 
            } 
        ], 
        "cat": "test1" 
    } 
] 

改为写入文件:

with open("out.json", "w+") as out: 
    json.dump(l, out, indent=4)