如何使用 python map() 函数来处理元组列表？

Question

我目前有两个列表和一个工作脚本，当给定 list_a 中的元素时，它会找到 list_b 中 30 分钟内的所有日期时间。社区在 .

中帮助了我

我用元组列表替换了其中一个列表，并一直试图在脚本中协调它——我将在下面解释我试图做出的一些修改。

# Old Set of Two Lists
list_a = ["10:26:42", "8:55:43", "7:34:11"]
list_b = ["10:49:20", "8:51:10", "10:34:35", "8:39:47", "7:11:49", "7:42:10"]

# Previous Output
10:26:42 is within 30m of 10:49:20, 10:34:35
08:55:43 is within 30m of 08:51:10, 08:39:47
07:34:11 is within 30m of 07:11:49, 07:42:10

# Old List and New List of Tuples
my_flights = ["10:26:42", "8:55:43", "7:34:11"]
alt_flights = [("10:49:20", "Frontier"), ("8:51:10", "Southwest"), ("10:34:35", "Jet Blue"), ("8:39:47", "Delta"), ("7:11:49", "Spirit"), ("7:42:10", "American"]

# Desired Output
10:26:42 is within 30m of Frontier, Jet Blue at 10:49:20, 10:34:35
10:26:42 is within 30m of Southwest, Delta at 08:51:10, 08:39:47
10:26:42 is within 30m of Spirit, American at 07:11:49, 07:42:10

旧的两个列表的工作脚本如下，我要做的是 (1) 将 list_a 替换为 my_flights (2) 替换 list_b使用 alt_flights 和 (3) 在我的输出中使用 alt_flights 中的名称！

def str2time(s):
    h,m,s = map(int, s.split(':'))
    return datetime.timedelta(hours=h, minutes=m, seconds

z = datetime.datetime(1900,1,1)

for a in map(str2time, list_a):
    start = f'{z+a:%H:%M:%S} is within 30m of'

    for b in map(str2time, list_b):
        if abs(a-b).total_seconds() <= 1800:
            print(f'{start} {z+b:%H:%M:%S}', end='')
            start = ','

    if start == ',':
        print()

尝试修改：我想我可以将 list_b 更改为 for b in map(str2time, alt_flights[0][0]) 并稍后引用 alt_flights[0][1] 以提取航空公司名称，但这会引发 str2time() 的错误。然后我想我可以在 if abs(a-b).total_seconds() <= 1800: 下面做一个检查，检查 if b in alt_flights 会获取当前航空公司名称值 list_b[0][1]。但是，这两个都失败了。

Answer 1

您有什么特殊原因需要使用map？

for b_time_str, b_name in alt_flights:
    b_time = str2time(b_time_str)
    if abs(a-b_time).total_seconds() <= 1800:
        print(f"{start} {z+b_time:%H:%M:%S} {b_name}")

Answer 2

与其在循环之前映射 alt_flights 中的时间，不如在打印期间将时间数据传递给 str2time 可能更易于阅读。如果你更换

for b in map(str2time, list_b):
    if abs(a-b).total_seconds() <= 1800:
        print(f'{start} {z+b:%H:%M:%S}', end='')

和

for time, airline in alt_flights:
    if abs(a - str2time(time)).total_seconds() <= 1800:
        print(f"{start} {str2time(time)} {airline}", end='')

代码将按预期运行。

完整的第二次迭代：

for a in map(str2time, my_flights):
    start = f'{z+a:%H:%M:%S} is within 30m of'

    for time, airline in alt_flights:
        if abs(a - str2time(time)).total_seconds() <= 1800:
            print(f"{start} {str2time(time)} {airline}", end='')
            start = ','

    if start == ',':
        print()

输出：

10:26:42 is within 30m of 10:49:20 Frontier, 10:34:35 Jet Blue
08:55:43 is within 30m of 8:51:10 Southwest, 8:39:47 Delta
07:34:11 is within 30m of 7:11:49 Spirit, 7:42:10 American

如何使用 python map() 函数来处理元组列表？

How can I use the python map() function to handle a list of tuples?

python

datetime

tuples

list

absolute-value