python regex for extracting data without

Question

Following is my input file

input.txt

min=1310ns median=1344ns max=1399ns first=2280ns
min=1293ns median=1331ns max=18400ns first=2284ns
min=1277ns median=1302ns max=1346ns first=2363ns

my python code

import re

input_file = open("input.txt", "r")
output_file = open("output.data", "w")

for line in input_file:
    match_defines = re.match(r'\s*min=([0-9]+)', line) # works fine
    match_defines = re.match(r'\s*min=([0-9]+) median=([0-9]+) max=([0-9]+) first=([0-9]+)', line) # this doesn't work. 

    if match_defines:
        newline1= "\n %s\t%s\t%s\t%s\n" % (match_defines.group(1), match_defines.group(2), match_defines.group(3), match_defines.group(4))
    output_file.write(newline1)

    else:
        output_file.write(line)

My expected result is

1310   1344   1399   2280
1293   1331   18400  2284
1277   1302   1346   2363

How do i modify my regex to get this.

Thanks for your answers.

Wiktor Stribiżew · Accepted Answer · 2015-12-07 12:17:10Z

1

You forgot to add ns in the regex:

\s*min=([0-9]+)ns median=([0-9]+)ns max=([0-9]+)ns first=([0-9]+)
               ^^                ^^             ^^

See regex demo

I suggest using named capture groups to make it easier to access the captures and perhaps use \s+ instead of literal spaces:

\s*min=(?P<min>[0-9]+)ns\s+median=(?P<median>[0-9]+)ns\s+max=(?P<max>[0-9]+)ns\s+first=(?P<first>[0-9]+)

See another demo

edited Dec 7, 2015 at 12:17

answered Dec 7, 2015 at 12:14

Wiktor Stribiżew

631k41 gold badges502 silver badges632 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

user2532296 Over a year ago

Thank you. I should have been a bit more careful

Wiktor Stribiżew Over a year ago

Also, I suggest using named captures, they are quite handy in situations when you have more than 2 groups.

Collectives™ on Stack Overflow

python regex for extracting data without

1 Answer 1

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related