从字典列表中提取字符串python

Question

I have below list of dictionaries.

self.local_devices_list =[
    {'type': '\x02', 'device_name': u'USB HID, ManufStr="", ProdStr="QWER1025", 
     SerialNum="ABCDEF0123456789", VendorID="0xa34", ProdID="0x4007"'},
    {'type': '\x02', 'device_name': u'USB HID, ManufStr="", ProdStr="ASDF452x", 
     SerialNum="ABCDEF0123456789", VendorID="0xa34", ProdID="0x4007"'}
]

I have extracted the value for key 'device_name' using the list comprehension

device_names = [d["device_name"].encode("utf-8") for d in self.local_devices_list if "device_name" in d]

I want to extract the information of device_name into separate strings like below

 1. ProdStr = QWER1025
 2. SerialNum = ABCDEF0123456789
 3. VendorID = 0xa34
 4. ProdID = 0x4007

Answer 1

A regex can solve this dict easily.

import re
regex = re.compile(r'(\w+)="(\w*)"', flags=re.IGNORECASE)
for d in device_names:
    print(dict(regex.findall(d)))

{'ManufStr': '', 'ProdStr': 'QWER1025', 'SerialNum': 'ABCDEF0123456789', 'VendorID': '0xa34', 'ProdID': '0x4007'}

{'ManufStr': '', 'ProdStr': 'ASDF452x', 'SerialNum': 'ABCDEF0123456789', 'VendorID': '0xa34', 'ProdID': '0x4007'}

Answer 2

You can use .values() and list(). values() will extract the values from the dictionary into a valueView, and list() will extract them to a list. If they are of string-type everything is good, otherwise you need to convert to string as you extract them from the list.

Eg:

ExtractedValues = list(self.local_devices_list.values())
str(ExtractedValues[0])

Answer 3

You can split your variable like this :

device_names[0].split(', ')

This will give you a lit of items that you should be able to process.

['USB HID', 'ManufStr=""', 'ProdStr="QWER1025"', 'SerialNum="ABCDEF0123456789"', 'VendorID="0xa34"', 'ProdID="0x4007"']

Hope this helps.

Answer 4

You can join them:

information = [[" ".join(t) for t in d.items()] for d in self.local_devices_list]

Just add the filters you need into the lists comprehension.