比方字符串:
user_info = '{"name" : "john", "gender" : "male", "age": 28}'
我们想把它转为下面的字典:
user_dict = {"name" : "john", "gender" : "male", "age": 28}
有以下几种要领:
1、经由过程json来转
>>> import json >>> user_info= '{"name" : "john", "gender" : "male", "age": 28}' >>> user_dict = json.loads(user_info) >>> user_dict {u'gender': u'male', u'age': 28, u'name': u'john'}
然则运用json举行转换存在一个潜伏的题目。
由json语法划定数组或对象当中的字符串必需运用双引号,不能运用单引号 (官网上有一段形貌是 “A string is a sequence of zero or more Unicode characters, wrapped in double quotes, using backslash escapes” )。因而下面的转换是毛病的:
>>> import json >>> user_info = "{'name' : 'john', 'gender' : 'male', 'age': 28}" # 因为字符串运用单引号,会致使运转失足 >>> user_dict = json.loads(user_info) Traceback (most recent call last): File "<stdin>", line 1, in <module> File "/usr/local/Cellar/python/2.7.11/Frameworks/Python.framework/Versions/2.7/lib/python2.7/json/__init__.py", line 339, in loads return _default_decoder.decode(s) File "/usr/local/Cellar/python/2.7.11/Frameworks/Python.framework/Versions/2.7/lib/python2.7/json/decoder.py", line 364, in decode obj, end = self.raw_decode(s, idx=_w(s, 0).end()) File "/usr/local/Cellar/python/2.7.11/Frameworks/Python.framework/Versions/2.7/lib/python2.7/json/decoder.py", line 380, in raw_decode obj, end = self.scan_once(s, idx) ValueError: Expecting property name: line 1 column 2 (char 1)
2、经由过程eval
>>> user_info = '{"name" : "john", "gender" : "male", "age": 28}' >>> user_dict = eval(user_info) >>> user_dict {'gender': 'male', 'age': 28, 'name': 'john'} >>> user_info = "{'name' : 'john', 'gender' : 'male', 'age': 28}" >>> user_dict = eval(user_info) >>> user_dict {'gender': 'male', 'age': 28, 'name': 'john'}
经由过程eval举行转换就不存在上面运用json举行转换的题目。然则,运用eval却存在平安性的题目。
3、经由过程 literal_eval
>>> import ast >>> user = '{"name" : "john", "gender" : "male", "age": 28}' >>> user_dict = ast.literal_eval(user) >>> user_dict {'gender': 'male', 'age': 28, 'name': 'john'} user_info = "{'name' : 'john', 'gender' : 'male', 'age': 28}" >>> user_dict = ast.literal_eval(user) >>> user_dict {'gender': 'male', 'age': 28, 'name': 'john'}
运用ast.literal_eval举行转换既不存在运用json举行转换的题目,也不存在运用 eval 举行转换的 平安性题目,因而引荐运用ast.literal_eval。
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