如何从 txt 文件中提取字符串（数字）并使用 python 中的正则表达式转换为整数

Question

read through and parse a file with text and numbers. extract all the numbers in the file and compute the sum of the numbers. txt file attached

This is for python 3 and above.

import re
names=open("regex_sum_319771_actual.txt")
numlist = list()
for files in names:
    files = files.rstrip()
    ext =re.findall('([0-9]+)',files)
    if len(ext)!= 1 :
        continue
    num = int(ext[0])
    numlist.append(num)
print('done',sum(numlist))


#the sum should give me an output ending with 689

Answer 1

that will work:

import re


with open("regex_sum_319771_actual.txt", "r") as f:
    nums = re.findall(r'([0-9]+)', f.read())
    print(sum([int(i) for i in nums]))

PS : do not forget to close your file after reading if you do not use with statement

Answer 2

You can iterate char by char.

import re
names = open("regex_sum_319771_actual.txt", 'r')
nbr = []
for line in names:
    for carac in line:
       if re.match(r'\d', carac):
            nbr.append(int(carac))

print(sum(nbr))
names.close()