Python time模块之时间处理与日期操作指南

import time

timestamp = time.time()
print(f"当前时间戳: {timestamp}")
# 输出示例: 当前时间戳: 1745315368.123456

local_time = time.localtime()
print(local_time)
# 输出: time.struct_time(tm_year=2026, tm_mon=8, tm_mday=22, tm_hour=15, tm_min=49, tm_sec=28, tm_wday=4, tm_yday=234, tm_isdst=0)

# 可以访问具体字段
print(f"年份: {local_time.tm_year}")
print(f"月份: {local_time.tm_mon}")
print(f"日期: {local_time.tm_mday}")

utc_time = time.gmtime()
print(utc_time)

formatted = time.strftime("%Y-%m-%d %H:%M:%S", local_time)
print(formatted)  # 输出: 2026-08-22 15:49:28

# 常用格式符：
# %Y: 四位年份
# %m: 月份（01-12）
# %d: 日期（01-31）
# %H: 小时（00-23）
# %M: 分钟（00-59）
# %S: 秒（00-59）
# %A: 星期全名
# %a: 星期缩写

time_str = "2026-08-22 15:49:28"
parsed_time = time.strptime(time_str, "%Y-%m-%d %H:%M:%S")
print(parsed_time)

print("开始休眠...")
time.sleep(2.5)  # 休眠 2.5 秒
print("休眠结束！")

start = time.perf_counter()

# 模拟耗时操作
time.sleep(0.1)

end = time.perf_counter()
print(f"操作耗时: {end - start:.6f} 秒")

start_cpu = time.process_time()

# 执行一些计算
sum(range(1000000))

end_cpu = time.process_time()
print(f"CPU 时间: {end_cpu - start_cpu:.6f} 秒")

# 结构化时间 -> 时间戳
struct_time = time.localtime()
timestamp_from_struct = time.mktime(struct_time)
print(f"转换回的时间戳: {timestamp_from_struct}")

# 时间戳 -> 结构化时间（本地）
new_struct = time.localtime(timestamp_from_struct)
print(new_struct)

readable = time.ctime()
print(readable)  # 输出: Fri Aug 22 15:49:28 2026

asc_time = time.asctime(local_time)
print(asc_time)  # 输出: Fri Aug 22 15:49:28 2026

print(f"本地时区偏移: {time.timezone} 秒")

import time

def expensive_function():
    total = 0
    for i in range(1000000):
        total += i
    return total

start = time.perf_counter()
result = expensive_function()
end = time.perf_counter()

print(f"函数结果: {result}")
print(f"执行时间: {end - start:.4f} 秒")

def log_message(level, message):
    timestamp = time.strftime("%Y-%m-%d %H:%M:%S")
    print(f"[{timestamp}] [{level}] {message}")

log_message("INFO", "程序启动成功")
time.sleep(1)
log_message("WARNING", "磁盘空间不足")

def countdown(seconds):
    for i in range(seconds, 0, -1):
        print(f"\r倒计时: {i} 秒", end="", flush=True)
        time.sleep(1)
    print("\r倒计时结束！")

countdown(5)