我可以编写 python 代码在执行期间自行修改吗？

Question

我是说，

target_ZCR_mean = sample_dataframe_summary['ZCR'][1]
target_ZCR_std = sample_dataframe_summary['ZCR'][2]
lower_ZCR_lim = target_ZCR_mean - target_ZCR_std
upper_ZCR_lim = target_ZCR_mean + target_ZCR_std

target_RMS_mean = sample_dataframe_summary['RMS'][1]
target_RMS_std = sample_dataframe_summary['RMS'][2]
lower_RMS_lim = target_RMS_mean - target_RMS_std
upper_RMS_lim = target_RMS_mean + target_RMS_std

target_TEMPO_mean = sample_dataframe_summary['Tempo'][1]
target_TEMPO_std = sample_dataframe_summary['Tempo'][2]
lower_TEMPO_lim = target_TEMPO_mean - target_TEMPO_std
upper_TEMPO_lim = target_TEMPO_mean + target_TEMPO_std

target_BEAT_SPACING_mean = sample_dataframe_summary['Beat Spacing'][1]
target_BEAT_SPACING_std = sample_dataframe_summary['Beat Spacing'][2]
lower_BEAT_SPACING_lim = target_BEAT_SPACING_mean - target_BEAT_SPACING_std
upper_BEAT_SPACING_lim = target_BEAT_SPACING_mean + target_BEAT_SPACING_std

四行代码的每一块都非常相似，除了几个字符。

我可以编写一个函数，一个 class 或其他一些代码，这样我就可以只将四行代码的模板包装到其中，并让它在运行时自行修改以获取代码执行上述代码的工作...?

对了，我用的是python3.6.

Answer 1

如果您发现自己存储了很多这样的变量，尤其是当它们相关时，几乎可以肯定有更好的方法。动态修改源永远不是解决方案。一种方法是使用函数来保留重复的逻辑，并使用 namedtuple 存储结果数据：

import collections
Data = collections.namedtuple('Data', 'mean, std, lower_lim, upper_lim')

def get_data(key, sample_dataframe_summary):
     mean = sample_dataframe_summary[key][1]
     std = sample_dataframe_summary[key][2]
     lower_lim = mean - std
     upper_lim = mean + std
     return Data(mean, std, lower_lim, upper_lim)

zcr = get_data('ZCR', sample_dataframe_summary)
rms = get_data('RMS', sample_dataframe_summary)
tempo = get_data('Tempo', sample_dataframe_summary)
beat_spacing = get_data('Beat Spacing', sample_dataframe_summary)

然后您可以使用 . 符号访问数据，例如 zcr.mean 和 tempo.upper_lim

我可以编写 python 代码在执行期间自行修改吗？

Can I write python code that modifies itself during execution?

python

self-modifying