CODEWITHSUNDEEP
python
learningpython
learningpython

Reputation: 1

Find a value for the match in string in python

Basically, I want to do following, I have a file full of such rows

Queue SIZE="1024" QID="8" TYPE="IOSQ" ADDRESS="0x218464000"

I need to do following,

If("IOSQ" in line): then capture the value of Address which is "0x218464000"

How do I script this in Python?

Upvotes: 0

Views: 71

Answers (3)

Jon Clements
Jon Clements

Reputation: 142146

One way is to use shlex.split to standardise the data (quotes etc..), then build a dict of key=value, then take the address (or blank) if the type is "IOSQ" otherwise leave the address as blank, eg:

import shlex

s = 'Queue SIZE="1024" QID="8" TYPE="IOSQ" ADDRESS="0x218464000"'
d = dict(el.partition('=')[::2] for el in shlex.split(s))
# {'QID': '8', 'TYPE': 'IOSQ', 'ADDRESS': '0x218464000', 'SIZE': '1024', 'Queue': ''}
address = d.get('ADDRESS', '') if d.get('TYPE') == 'IOSQ' else ''
# '0x218464000'

This has the advantage that you're not relying on the ordering of key="something" in the text being the same and you can always access values for other keys if needs be later.

Upvotes: 0

cizixs
cizixs

Reputation: 13981

If the data are well-formatted, you might consider this:

lst = 'Queue SIZE="1024" QID="8" TYPE="IOSQ" ADDRESS="0x218464000"'.split()

def make_dict(lst):
    return dict([tuple(item.split('=')) for item in lst])

dic = {}
dic[lst[0]] = make_dict(lst[1:])
print dic

Which gives:

{'Queue': {'QID': '"8"', 'ADDRESS': '"0x218464000"', 'TYPE': '"IOSQ"', 'SIZE': '"1024"'}}

Then you can access the value dic[lst[0]].get('ADDRESS', 'no address').strip('"').

Upvotes: 0

user
user

Reputation: 5696

You can use regular expressions. 

import re

my_string = 'Queue SIZE="1024" QID="8" TYPE="IOSQ" ADDRESS="0x218464000"'

pattern = re.compile(r'IOSQ.*?ADDRESS="(\dx\d+)')    
matches = re.findall(pattern, my_string)

print(matches)

The pattern is r'IOSQ.*?="(\dx\d+). r'something' is a raw string, you should use this always. Then IOSQ requires exact match of those letters. .*? means match any character, from 0 to as few as possible (until a full match is found). Parenthesis makes findall return only the contents of the parenthesis. \d means digits 0 to 9. + means one or more of the previous character being matched.

Upvotes: 2

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