如何截取子字符串？移除时间字符串秒数的实现方法

方法一：正则表达式替换 #

通过正则精准匹配并移除秒数部分，确保只针对时间里的秒数进行修改：

Python 示例

import re

time_strings = ["9:00:10 AM", "12:10:20 PM"]
pattern = r":\d{2}(?= [AP]M)"  # 匹配冒号+两位数字，且后面紧跟空格和AM/PM
cleaned_times = [re.sub(pattern, "", s) for s in time_strings]
print(cleaned_times)  # 输出: ['9:00 AM', '12:10 PM']

JavaScript 示例

const timeStrings = ["9:00:10 AM", "12:10:20 PM"];
const pattern = /:\d{2}(?= [AP]M)/g;
const cleanedTimes = timeStrings.map(s => s.replace(pattern, ""));
console.log(cleanedTimes); // 输出: ['9:00 AM', '12:10 PM']

方法二：时间库解析后重新格式化（Python） #

借助时间处理库解析原时间字符串，再重新格式化为不含秒数的样式：

from datetime import datetime

time_strings = ["9:00:10 AM", "12:10:20 PM"]
cleaned_times = []
for s in time_strings:
    # 解析原时间字符串
    time_obj = datetime.strptime(s, "%I:%M:%S %p")
    # 格式化为不带秒的12小时制时间，去掉小时前的前导零
    formatted = time_obj.strftime("%I:%M %p").lstrip('0')
    cleaned_times.append(formatted)
print(cleaned_times)  # 输出: ['9:00 AM', '12:10 PM']

内容的提问来源于stack exchange，提问作者Otis