在 Python 中获取字符串中的数字

Question

I have a log file that looks as follows (only gave a subset):

isp:29.455.3.53
completed in 24ms (Count: 34, DB: 4)

isp:34.233.3.43
completed in 51ms (Count: 21, DB 4)

I have each log as a separate string. What is the best way for me to extract the count number so then I can use it get a total count number ie I want to extract the 34 and 21 so I can add them together.

I want to do this in Python 2.7.5 but I'm not really sure where to begin.

Any help would be greatly appreciated.

Answer 1

You can use re.findall() to get a list of the counts as strings. Then you just need to convert the strings to integers and sum them up:

import re

s = """isp:29.455.3.53
completed in 24ms (Count: 34, DB: 4)

isp:34.233.3.43
completed in 51ms (Count: 21, DB 4)
"""

sum = 0

for count in re.findall('Count: (\d+)', s):
    sum += int(count)

print(sum)

Answer 2

Supposing the log file abc.txt contains these lines:

isp:29.455.3.53
completed in 24ms (Count: 34, DB: 4)

isp:34.233.3.43
completed in 51ms (Count: 21, DB 4)

Read the log file with and for each line that begins with completed , search for the text inside parenthesis and find the number.

with open('abc.txt') as fp:
for eachline in fp:
    if 'completed' in eachline:
        text = eachline[eachline.find("(")+1:eachline.find(")")]
        num = text.split(',')[0].split()[1]
        print num

Answer 3

If you are only looking at lines starting with "completed" and the format is consistent (as I asked in the comments above) then this will extract the value you want as an integer

In [20]: s="completed in 51ms (Count: 21, DB 4)"

In [21]: int(s.split('Count:')[1].split(',')[0])
Out[21]: 21

You could use regular expressions too as an alternative, but I favor " Simple is better than complex ."

Answer 4

x = 0

with open('\path\file.txt') as log:
    for line in log:
        if line.split(' ')[0] = completed:
            x += int(line.split(' ')[4][:-1])

print x

This will dump the count into variable x. You need to open the file first and iterate over it with the for loop. The first if checks to see if the line starts with completed. If it does, then the second line grabs the number, subtracts the comma, converts to an int, and adds to x.

Note that this will only work if the log file is formated uniform exactly like you have in the example. Otherwise you may want to mess with regexes.