从列表中的字符串中提取值-python

Question

I have a list in my python code with the following structure:

file_info = ['{file:C:\\samples\\123.exe, directory:C:\\}','{file:C:\\samples\\345.exe, directory:C:\\}',...]

I want to extract just the file and directory values for every value of the list and print it. With the following code, I am able to extract the directory values:

for item in file_info:

    print item.split('directory:')[1].strip('}')

But I am not able to figure out a way to extract the 'file' values. The following doesn't work:

print item.split('file:')[1].strip(', directory:C:\}')

Suggestions? If there is any better method to extract the file and directory values other than this, that would be great too. Thanks in advance.

Answer 1

If the format is exactly the same you've provided, you'd better go with using re :

import re

file_info = ['{file:file1, directory:dir1}', '{file:file2, directory:directory2}']

pattern = re.compile(r'\w+:(\w+)')
for item in file_info:
    print re.findall(pattern, item)

or, using string replace() , strip() and split() (a bit hackish and fragile):

file_info = ['{file:file1, directory:dir1}', '{file:file2, directory:directory2}']

for item in file_info:
    item = item.strip('}{').replace('file:', '').replace('directory:', '')
    print item.split(', ')

both code snippets print:

['file1', 'dir1']
['file2', 'directory2']

---

If the file_info items are just dumped json items (watch the double quotes), you can use json to load them into dictionaries:

import json

file_info = ['{"file":"file1", "directory":"dir1"}', '{"file":"file2", "directory":"directory2"}']

for item in file_info:
    item = json.loads(item)
    print item['file'], item['directory']

or, literal_eval() :

from ast import literal_eval

file_info = ['{"file":"file1", "directory":"dir1"}', '{"file":"file2", "directory":"directory2"}']

for item in file_info:
    item = literal_eval(item)
    print item['file'], item['directory']

both code snippets print:

file1 dir1
file2 directory2

Hope that helps.

Answer 2

I would do:

import re

regx = re.compile('{\s*file\s*:\s*([^,\s]+)\s*'
                  ','
                  '\s*directory\s*:\s*([^}\s]+)\s*}')

file_info = ['{file:C:\\samples\\123.exe, directory  :  C:\\}',
             '{  file:  C:\\samples\\345.exe,directory:C:\\}'
             ]

for item in file_info:
    print '%r\n%s\n' % (item,
                        regx.search(item).groups())

result

'{file:C:\\samples\\123.exe, directory  :  C:\\}'
('C:\\samples\\123.exe', 'C:\\')

'{  file:  C:\\samples\\345.exe,directory:C:\\}'
('C:\\samples\\345.exe', 'C:\\')