如何使用Python打印指定月份范围内的交易日志

需求描述 #

需要从trans.txt交易日志中按月份范围筛选日志，支持季度/半年度统计，当前本地时间为11月时，可筛选9-11月的季度日志。

日志文件trans.txt示例内容：

22 July 2021 09:35:54 Withdrawn: RM500
22 July 2021 09:35:54 Withdrawn: RM500
22 August 2021 09:35:54 Withdrawn: RM500
22 August 2021 09:35:54 Withdrawn: RM500
22 September 2021 09:35:54 Withdrawn: RM500
22 September 2021 09:35:54 Withdrawn: RM500
22 September 2021 09:35:54 Withdrawn: RM500
22 October 2021 09:35:54 Withdrawn: RM500
22 October 2021 09:35:54 Withdrawn: RM500
22 November 2021 09:35:54 Withdrawn: RM500
22 November 2021 09:35:54 Withdrawn: RM500
22 December 2021 09:35:54 Withdrawn: RM500
22 December 2021 09:35:54 Withdrawn: RM500

原有代码问题分析 #

• 仅匹配当前本地月份的第一条日志就倒序截取全部内容，未做月份范围筛选逻辑
• 硬编码截取前3行，未考虑每个月日志数量不固定的场景
• 未兼容跨年月份筛选场景，也未把月份映射为数字做范围判断

修改后可运行代码 #

import time

# 月份英文名称到数字的映射，用于范围判断
month_map = {
    "January": 1, "February": 2, "March": 3, "April": 4, "May": 5, "June":6,
    "July":7, "August":8, "September":9, "October":10, "November":11, "December":12
}

# 获取本地当前月份数字
current_month = int(time.strftime("%m"))
# 配置筛选月份数量，设置3为季度，设置6即为半年度
filter_month_count = 3
min_month = current_month - filter_month_count + 1

# 读取交易日志
with open("trans.txt", "r", encoding="utf-8") as f:
    log_lines = f.read().splitlines()

# 筛选符合月份范围的日志
matched_logs = []
for line in log_lines:
    if not line.strip():
        continue
    log_month_str = line.split()[1]
    log_month = month_map.get(log_month_str, 0)
    # 兼容跨年场景判断
    if min_month > 0:
        if min_month <= log_month <= current_month:
            matched_logs.append(line)
    else:
        # 跨年时自动处理12月等上年月份匹配
        if log_month >= (min_month + 12) or log_month <= current_month:
            matched_logs.append(line)

# 输出到终端同时写入临时文件
with open("tempLogs.txt", "w", encoding="utf-8") as f:
    for log in matched_logs:
        print(log)
        f.write(log + "\n")

功能说明 #

• 可通过修改filter_month_count参数灵活调整筛选范围
• 自动兼容跨年月份筛选场景，比如当前月为2月时，可自动筛选12、1、2月的日志
• 自动适配每个月的日志数量，不会漏匹配同月份的多条日志
• 筛选结果同时输出到终端和tempLogs.txt文件

内容的提问来源于stack exchange，提问作者Darren LK