如何将字典的str表示,如下面的字符串,转换为字典?
s = "{'muffin' : 'lolz', 'foo' : 'kitty'}"
我不喜欢使用eval。我还能用什么?
主要原因是,我同事写的一个类,将所有输入转换为字符串。我没有心情去修改他的课程,去处理这个问题。
如何将字典的str表示,如下面的字符串,转换为字典?
s = "{'muffin' : 'lolz', 'foo' : 'kitty'}"
我不喜欢使用eval。我还能用什么?
主要原因是,我同事写的一个类,将所有输入转换为字符串。我没有心情去修改他的课程,去处理这个问题。
当前回答
string = "{'server1':'value','server2':'value'}"
#Now removing { and }
s = string.replace("{" ,"")
finalstring = s.replace("}" , "")
#Splitting the string based on , we get key value pairs
list = finalstring.split(",")
dictionary ={}
for i in list:
#Get Key Value pairs separately to store in dictionary
keyvalue = i.split(":")
#Replacing the single quotes in the leading.
m= keyvalue[0].strip('\'')
m = m.replace("\"", "")
dictionary[m] = keyvalue[1].strip('"\'')
print dictionary
其他回答
如果字符串始终是可信的,则可以使用eval(或建议使用literal_eval;不管字符串是什么,它都是安全的。)否则,您需要一个解析器。JSON解析器(例如simplejson)如果只存储符合JSON方案的内容,那么它就可以工作。
string = "{'server1':'value','server2':'value'}"
#Now removing { and }
s = string.replace("{" ,"")
finalstring = s.replace("}" , "")
#Splitting the string based on , we get key value pairs
list = finalstring.split(",")
dictionary ={}
for i in list:
#Get Key Value pairs separately to store in dictionary
keyvalue = i.split(":")
#Replacing the single quotes in the leading.
m= keyvalue[0].strip('\'')
m = m.replace("\"", "")
dictionary[m] = keyvalue[1].strip('"\'')
print dictionary
你可以使用内置的ast.literal_eval:
>>> import ast
>>> ast.literal_eval("{'muffin' : 'lolz', 'foo' : 'kitty'}")
{'muffin': 'lolz', 'foo': 'kitty'}
这比使用eval更安全。正如它自己的文件所说:
>>> help(ast.literal_eval) Help on function literal_eval in module ast: literal_eval(node_or_string) Safely evaluate an expression node or a string containing a Python expression. The string or node provided may only consist of the following Python literal structures: strings, numbers, tuples, lists, dicts, booleans, and None.
例如:
>>> eval("shutil.rmtree('mongo')")
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "<string>", line 1, in <module>
File "/opt/Python-2.6.1/lib/python2.6/shutil.py", line 208, in rmtree
onerror(os.listdir, path, sys.exc_info())
File "/opt/Python-2.6.1/lib/python2.6/shutil.py", line 206, in rmtree
names = os.listdir(path)
OSError: [Errno 2] No such file or directory: 'mongo'
>>> ast.literal_eval("shutil.rmtree('mongo')")
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/opt/Python-2.6.1/lib/python2.6/ast.py", line 68, in literal_eval
return _convert(node_or_string)
File "/opt/Python-2.6.1/lib/python2.6/ast.py", line 67, in _convert
raise ValueError('malformed string')
ValueError: malformed string
总结:
import ast, yaml, json, timeit
descs=['short string','long string']
strings=['{"809001":2,"848545":2,"565828":1}','{"2979":1,"30581":1,"7296":1,"127256":1,"18803":2,"41619":1,"41312":1,"16837":1,"7253":1,"70075":1,"3453":1,"4126":1,"23599":1,"11465":3,"19172":1,"4019":1,"4775":1,"64225":1,"3235":2,"15593":1,"7528":1,"176840":1,"40022":1,"152854":1,"9878":1,"16156":1,"6512":1,"4138":1,"11090":1,"12259":1,"4934":1,"65581":1,"9747":2,"18290":1,"107981":1,"459762":1,"23177":1,"23246":1,"3591":1,"3671":1,"5767":1,"3930":1,"89507":2,"19293":1,"92797":1,"32444":2,"70089":1,"46549":1,"30988":1,"4613":1,"14042":1,"26298":1,"222972":1,"2982":1,"3932":1,"11134":1,"3084":1,"6516":1,"486617":1,"14475":2,"2127":1,"51359":1,"2662":1,"4121":1,"53848":2,"552967":1,"204081":1,"5675":2,"32433":1,"92448":1}']
funcs=[json.loads,eval,ast.literal_eval,yaml.load]
for desc,string in zip(descs,strings):
print('***',desc,'***')
print('')
for func in funcs:
print(func.__module__+' '+func.__name__+':')
%timeit func(string)
print('')
结果:
*** short string ***
json loads:
4.47 µs ± 33.4 ns per loop (mean ± std. dev. of 7 runs, 100000 loops each)
builtins eval:
24.1 µs ± 163 ns per loop (mean ± std. dev. of 7 runs, 10000 loops each)
ast literal_eval:
30.4 µs ± 299 ns per loop (mean ± std. dev. of 7 runs, 10000 loops each)
yaml load:
504 µs ± 1.29 µs per loop (mean ± std. dev. of 7 runs, 1000 loops each)
*** long string ***
json loads:
29.6 µs ± 230 ns per loop (mean ± std. dev. of 7 runs, 10000 loops each)
builtins eval:
219 µs ± 3.92 µs per loop (mean ± std. dev. of 7 runs, 1000 loops each)
ast literal_eval:
331 µs ± 1.89 µs per loop (mean ± std. dev. of 7 runs, 1000 loops each)
yaml load:
9.02 ms ± 92.2 µs per loop (mean ± std. dev. of 7 runs, 100 loops each)
结论: 喜欢json.loads
我的字符串里面没有引号: s = '日期:2022-11-29T10:57:01.024Z,大小:910.11 KB'
我的解决方案是使用str.split: {k: k v, v在地图(λd: d.split(“:”),s.split (" ")}