如何在Python中从文本文件的行中提取数字

import re

def extract_numbers_from_file(filename):
    numbers = []
    with open(filename, 'r') as file:
        for line in file:
            matches = re.findall(r'\d+', line)
            numbers.extend(matches)
    return numbers

filename = 'example.txt'
numbers = extract_numbers_from_file(filename)
print(numbers)

def extract_numbers_from_file(filename):
    numbers = []
    with open(filename, 'r') as file:
        for line in file:
            line = line.strip()  # 去除行首行尾的空白字符
            if line.isdigit():  # 判断是否为数字
                numbers.append(line)
    return numbers

filename = 'example.txt'
numbers = extract_numbers_from_file(filename)
print(numbers)