Question

我使用Python的正则表达式从典型的科学模拟日志文件中获取少量值。此日志文件的缩短版本如下所示：

Time = 500

smoothSolver:  Solving for Ux, Initial residual = 0.000185956, Final residual = 8.56685e-06, No Iterations 4
smoothSolver:  Solving for Uy, Initial residual = 0.00338876, Final residual = 0.00016085, No Iterations 4
smoothSolver:  Solving for Uz, Initial residual = 0.00412929, Final residual = 0.000195655, No Iterations 4
GAMG:  Solving for p, Initial residual = 0.0135009, Final residual = 0.000416508, No Iterations 2
time step continuity errors : sum local = 8.12599e-05, global = -2.7703e-06, cumulative = -0.0058176
smoothSolver:  Solving for omega, Initial residual = 6.29185e-05, Final residual = 4.26272e-06, No Iterations 3
smoothSolver:  Solving for k, Initial residual = 0.000658395, Final residual = 4.89427e-05, No Iterations 3
ExecutionTime = 537.04 s  ClockTime = 537 s

我的代码是：

with open(logFile, 'r') as logfile_read:
    for line in logfile_read:
        line = line.rstrip()

        if 'Time' in line:
            iteration_time = re.findall(r'^Time\s+=\s+(.*)', line)

        if ('local' or 'global' or 'cumulative') in line:
            local_global_cumu = re.search(r'sum\s+local\s+=\s+(.*),\s+global\s+=\s+(.*),\s+cumulative\s+=\s+(.*)', line)
            if local_global_cumu:
                contLocal_0_value = local_global_cumu.group(1)
                contGlobal_0_value = local_global_cumu.group(2)
                contCumulative_0_value = local_global_cumu.group(3)

            contLocal_0_time_value = zip(iteration_time,contLocal_0_value)
            print contLocal_0_value
            print contLocal_0_time_value

我得到的输出是：

8.12599e-05
[('500', '8')]

在zip()之后，值8.12599e-05被截断为8

为什么zip()会发生这种情况以及如何解决这个问题？我无法在float()中使用zip()。

Answer 1

来自zip＆＃39的doc：

The returned list is truncated in length to the length of the shortest argument sequence.

您正在使用字符串['500']压缩列表'8.12599e-05'，因此结果为[('500', '8')]。

我不确定你要做什么，但你可能意味着

zip(iteration_time, [contLocal_0_value])

Answer 2

问题是contLocal_0_value是字符串而非列表，因此您需要使用zip(iteration_time, [contLocal_0_value])。

import re

with open(logFile, 'r') as logfile_read:
    for line in logfile_read:
        line = line.rstrip()

        if 'Time' in line:
            iteration_time = re.findall(r'^Time\s+=\s+(.*)', line)

        if ('local' or 'global' or 'cumulative') in line:
            local_global_cumu = re.search(
                (r'sum\s+local\s+=\s+(.*),\s+global\s+=\s+(.*),'
                    r'\s+cumulative\s+=\s+(.*)'),
                line)
            if local_global_cumu:
                contLocal_0_value = local_global_cumu.group(1)
                contGlobal_0_value = local_global_cumu.group(2)
                contCumulative_0_value = local_global_cumu.group(3)

            contLocal_0_time_value = zip(iteration_time, [contLocal_0_value])
            print contLocal_0_value
            print contLocal_0_time_value

输出：

8.12599e-05
[('500', '8.12599e-05')]

Python中的Zip函数截断浮动数字

2 个答案: