JSON (JavaScript Object Notation, JS object tag) is a lightweight data exchange format. The data format of JSON is actually the dictionary format in python, which can contain arrays enclosed in square brackets, which are lists in python.
In python, there are modules that specifically handle json format - json and picle modules
The Json module provides four methods: dumps, dump, loads, load
The pickle module also provides four functions: dumps, dump, loads, load
1. dumps and dump:
dumps and dump Serialization method
dumps has only been completed Serialize to str,
dump must pass the file descriptor, and save the serialized str to the file
View source code:
def dumps(obj, skipkeys=False, ensure_ascii=True, check_circular=True, allow_nan=True, cls=None, indent=None, separators=None, default=None, sort_keys=False, **kw): # Serialize ``obj`` to a JSON formatted ``str``. # 序列号 “obj” 数据类型 转换为 JSON格式的字符串 def dump(obj, fp, skipkeys=False, ensure_ascii=True, check_circular=True, allow_nan=True, cls=None, indent=None, separators=None, default=None, sort_keys=False, **kw): """Serialize ``obj`` as a JSON formatted stream to ``fp`` (a ``.write()``-supporting file-like object).
Sample code:
>>> import json >>> json.dumps([]) # dumps可以格式化所有的基本数据类型为字符串 '[]' >>> json.dumps(1) # 数字 '1' >>> json.dumps('1') # 字符串 '"1"' >>> dict = {"name":"Tom", "age":23} >>> json.dumps(dict) # 字典 '{"name": "Tom", "age": 23}'
a = {"name":"Tom", "age":23} with open("test.json", "w", encoding='utf-8') as f: # indent 超级好用,格式化保存字典,默认为None,小于0为零个空格 f.write(json.dumps(a, indent=4)) # json.dump(a,f,indent=4) # 和上面的效果一样
2. loads and load
loads and load Deserialization method
loads only completes deserialization,
load only receives file descriptors, completed Reading files and deserializing
View source code:
def loads(s, encoding=None, cls=None, object_hook=None, parse_float=None, parse_int=None, parse_constant=None, object_pairs_hook=None, **kw): """Deserialize ``s`` (a ``str`` instance containing a JSON document) to a Python object. 将包含str类型的JSON文档反序列化为一个python对象""" def load(fp, cls=None, object_hook=None, parse_float=None, parse_int=None, parse_constant=None, object_pairs_hook=None, **kw): """Deserialize ``fp`` (a ``.read()``-supporting file-like object containing a JSON document) to a Python object. 将一个包含JSON格式数据的可读文件饭序列化为一个python对象"""
Example:
>>> json.loads('{"name":"Tom", "age":23}') {'age': 23, 'name': 'Tom'}
import json with open("test.json", "r", encoding='utf-8') as f: aa = json.loads(f.read()) f.seek(0) bb = json.load(f) # 与 json.loads(f.read())print(aa)print(bb)# 输出:{'name': 'Tom', 'age': 23} {'name': 'Tom', 'age': 23}
The above is the detailed content of How to use python json module. For more information, please follow other related articles on the PHP Chinese website!