获取部分字符的步骤

text = "Hello, World!"
substring = text[7:12]  # 提取从索引7到11的字符（不包括索引12）
print(substring)  # 输出: "World"

let text = "Hello, World!";
let substring = text.substring(7, 12);  // 提取从索引7到11的字符
console.log(substring);  // 输出: "World"

import re

text = "Hello, World! Today is 2023-10-05."
pattern = r'\d{4}-\d{2}-\d{2}'  # 匹配日期格式 YYYY-MM-DD
match = re.search(pattern, text)
if match:
    date = match.group()
    print(date)  # 输出: "2023-10-05"

text = "Hello, World!"
start_index = 7
end_index = 20
if start_index < len(text) and end_index <= len(text):
    substring = text[start_index:end_index]
    print(substring)
else:
    print("索引越界")