如何批量生成类实例的属性？

Question

我有一个名为 MyClass 的 class。我想在生成 class 的 instances 时生成 batches 中的 instance 的 attributes k_10sec 到 k_1d。

如何修改代码？

bars = ['10sec', '1min', '5min', '30min', '1d']


class MyClass:
    def __init__(self):
        for bar in bars:
            if bar.endswith('sec'):
                duration_seconds = int(bar[:-3])
            elif bar.endswith('min'):
                duration_seconds = int(bar[:-3] * 60)
            elif bar.endswith('d'):
                duration_seconds = int(bar[:-1] * 60 * 60 * 24)
            self.globals()[f'k_{bar}'] = duration_seconds


s1 = MyClass()
for bar in bars:
    print(s1.[f'k_{bar}'])

我的预期结果：

最后我把这两种方法结合起来一起使用了

import re


def parse_time(bar='', secs=0):
    if bar != '':
        bar = re.split('(\d+)', bar)
        if bar[2] in ('sec', 's'):
            secs = int(bar[1])
        elif bar[2] == 'min':
            secs = int(bar[1]) * 60
        elif bar[2] in ('hour', 'h'):
            secs = int(bar[1]) * 60 * 60
        elif bar[2] in ('d', 'day', 'D'):
            secs = int(bar[1]) * 60 * 60 * 24
        else:
            pass
        return secs
    elif secs != 0:
        if secs % (60 * 60 * 24) == 0:
            bar = str(secs // (60 * 60 * 24)) + 'day'
        elif secs % (60 * 60) == 0:
            bar = str(secs // (60 * 60)) + 'hour'
        elif secs % 60 == 0:
            bar = str(secs // 60) + 'min'
        else:
            bar = str(secs) + 'sec'
        return bar
    else:
        pass


class MyClass:
    def __init__(self, bars):
        self.d = {f'k_{bar}': parse_time(bar=bar) for bar in bars}


if __name__ == '__main__':
    bars = ['10sec', '1min', '5min', '30min', '1d']
    s1 = MyClass(bars)
    pass

Answer 1

你不需要globals；这是内置作用域中的一个函数，用于为全局变量提供 dict 接口。只需使用常规 dict

class MyClass:
    def __init__(self, bars):
        self.d = {}
        for bar in bars:
            if bar.endswith('sec'):
                duration_seconds = int(bar[:-3])
            elif bar.endswith('min'):
                duration_seconds = int(bar[:-3]) * 60
            elif bar.endswith('d'):
                duration_seconds = int(bar[:-1]) * 60 * 60 * 24
            self.d[f'k_{bar}'] = duration_seconds

s1 = MyClass(['10sec', '1min', '5min', '30min', '1d'])
for bar in s1.d:
    print(s1.d[bar])

不过，我会将把时间字符串转换为秒数的逻辑移到一个单独的函数中：

def parse_time(s):
    if s.endswith('sec'):
        return int(s[:-3])
    elif s.endswith('min'):
        return int(s[:-3]) * 60
    elif s.endswith('d'):
        return int(s[:-1]) * 60 * 60 * 24


class MyClass:
    def __init__(self, bars):
        self.d = {f'k_{bar}': parse_time(bar) for bar in bars}

Answer 2

我写了一个非常简单的解决方案，希望是你的意图

import re

bars = ['10sec', '1min', '5min', '30min', '1d']

class MyClass:
    def duration_seconds(self, bar):
        bar = re.split('(\d+)', bar)
        if bar[2] == 'sec':
            secs = int(bar[1])
        elif bar[2] == 'min':
            secs = int(bar[1]) * 60
        elif bar[2] == 'd':
            secs = int(bar[1]) * 60 * 60 * 24
        return secs


s1 = MyClass()
for bar in bars:
    print(s1.duration_seconds('k_{0}'.format(bar)))

如何批量生成类实例的属性？

How to generate properties of instances of classes in batches?

python

python-class

variable-variables