Python string.split 不符合我的预期

Question

I have a string with a bunch of weirdness in it that I'd like to break up into a list:

"44":{"1":4.6,"0":1.53,"2":7.2},"53":{"1":4.2,"0":1.4,"2":6.75},"121":{"1":3.2,"0":1.6,"2":6}

Ideally, I'd like:

"44":{"1":4.6,"0":1.53,"2":7.2}
"53":{"1":4.2,"0":1.4,"2":6.75}
"121":{"1":3.2,"0":1.6,"2":6}

But I'd settle for splitting at each }.

mystring.split('}') seems to split my string into a list with one element per character for some reason. Not sure what I'm doing wrong. Help!

Answer 1

That almost looks like valid JSON.

>>> s = '"44":{"1":4.6,"0":1.53,"2":7.2},"53":{"1":4.2,"0":1.4,"2":6.75},"121":{"1":3.2,"0":1.6,"2":6}'
>>> import json
>>> d = json.loads("{" + s + "}")
>>> d
{'53': {'2': 6.75, '0': 1.4, '1': 4.2}, '44': {'2': 7.2, '0': 1.53, '1': 4.6}, '
121': {'2': 6, '0': 1.6, '1': 3.2}}
>>> for key,value in d.items():
...    print("Key: {0} - Value: {1}".format(key,value))
...
Key: 53 - Value: {'2': 6.75, '0': 1.4, '1': 4.2}
Key: 44 - Value: {'2': 7.2, '0': 1.53, '1': 4.6}
Key: 121 - Value: {'2': 6, '0': 1.6, '1': 3.2}

Answer 2

You could try this:

s = '"44":{"1":4.6,"0":1.53,"2":7.2},"53":{"1":4.2,"0":1.4,"2":6.75},"121":{"1":3.2,"0":1.6,"2":6}'
h = eval("{"+s+"}")
for k in h: print k,h[k]

but since eval is not safe as it can execute arbitrary code, it is much better to use literal_eval. literal_eval only works on valid data types:

from ast import literal_eval
s = # ....
h = literal_eval("{"+s+"}")
for k in h: print k,h[k]

Output

121 {'1': 3.2, '0': 1.6, '2': 6}
44 {'1': 4.6, '0': 1.53, '2': 7.2}
53 {'1': 4.2, '0': 1.4, '2': 6.75}

Answer 3

You can do something like this:

>>> string = '"44":{"1":4.6,"0":1.53,"2":7.2},"53":{"1":4.2,"0":1.4,"2":6.75},"121":{"1":3.2,"0":1.6,"2":6}'
>>> string.replace('},','}***').split('***')
['"44":{"1":4.6,"0":1.53,"2":7.2}', '"53":{"1":4.2,"0":1.4,"2":6.75}', '"121":      {"1":3.2,"0":1.6,"2":6}']

Answer 4

Correct answer to your questions depends on what kind of expressions are allowed. If an expression may contain nested braces, then you need recursive regular expression. The following solution doesn't support nested braces, but it's enough to parse your sample:

    for token in re.findall(r'((?:[^{,]|{.*?})+)', mystring):
        print token

Answer 5

Your input is nearly JSON; it's the contents of a dict, just missing the enclosing braces :

import json
nearly_json = '"44":{"1":4.6,"0":1.53,"2":7.2},"53":{"1":4.2,"0":1.4,"2":6.75},"121":{"1":3.2,"0":1.6,"2":6}'

d = json.loads(f'{{ {nearly_json} }}') # Add the missing enclosing braces, and convert to Python (deserialize)...

d
{'44': {'1': 4.6, '0': 1.53, '2': 7.2}, '53': {'1': 4.2, '0': 1.4, '2': 6.75}, '121': {'1': 3.2, '0': 1.6, '2': 6}}

d['44']
{'1': 4.6, '0': 1.53, '2': 7.2}

As TimPietzcker said you can now iterate over the dict eg with .items() Or you can access its .keys()

Answer 6

Just split on the comma?

print '"44":{"1":4.6,"0":1.53,"2":7.2},"53":{"1":4.2,"0":1.4,"2":6.75},"121":{"1":3.2,"0":1.6,"2":6}'.split(',')

gives:

['"44":{"1":4.6', '"0":1.53', '"2":7.2}', '"53":{"1":4.2', '"0":1.4', '"2":6.75}', '"121":{"1":3.2', '"0":1.6', '"2":6}']

which is what you asked for.