1线正则表达式可汇总txt文件中的数字

Question

Just started learning python and wonder how does one sum up all the numbers in a txt file with regex and list compression.

I wrote the following but not sure how to avoid adding up numbers from empty lists in the findall search:

import re

print (sum([int(num[0]) for num[0] in re.findall('[0-9]+', open('xxx.txt').read().split())]))

Answer 1

You don't need to split the input data since re.findall should work on fileobj.read() . And also don't specify the index on the intermediate variable while iterating over the resultant list of re.findall .

print (sum(int(num) for num in re.findall('[0-9]+', open('xxx.txt').read())))

Answer 2

With \\d+ you will not have empty strings. With map you will convert all your strings to integer and then sum them up with sum().

print(sum(map(int, re.findall('\d+', open('xxx.txt').read()))))