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python - 将多个变量声明为同一类型

问题描述

问题：我有一个接受参数的函数n和base，我想确保这两个参数实际上都是整数。到目前为止，我已经完成了以下工作：

#  Conditions in which the function makes sense.
assert isinstance(n, (int)), 'n must be an integer. n: {0}'.format(n)
assert isinstance(base, (int)), 'base must be an integer. base: {0}'.format(base)
assert not isinstance(n, bool)

问题：这似乎很乏味，我想以某种方式做一些类似于assert isinstance((n, base), (int, int)), 'n and base must be integers. n: {0}, base: {1}'.format(n, base). 但这在意外时间给了我一个 AssertionError （n并且base都是 int）。也许不能使用元组？有没有类似的方法有效？

编辑：我想一个理想的处理方法是列出每个应该是 t 类型的参数，如果一个或多个失败，只打印失败的那些。

为了完整起见，下面是整个代码。我不认为它会有用，但我可能弄错了。它不是任何东西的一部分，我只是在查看此处的另一个问题后使用可选参数。

def pascal(n, base=1):
    """Makes a dictionary where the keys are row-indexes in a pascal-trangle
    of size n, and the values are the rows as a list. E.g. pascal(3) should
    return {1 : [1], 2: [1,1], 3: [1,2,1]}.

    pascal(0) should returns an empty dictionary.

    Optional argument 'base=': set an integer as a new base. E.g.
    pascal(3, base=2) should return {1: [2], 2: [2, 2], 3: [2, 4, 2]}"""

    #  Conditions in which the function makes sense.
    #  assert isinstance((n, base), (int, int)), 'n and base must be integers. n: {0}, base: {1}'.format(n, base)
    assert isinstance(n, (int)), 'n must be an integer. n: {0}'.format(n)
    assert isinstance(base, (int)), 'base must be an integer. base: {0}'.format(base)
    assert not isinstance(n, bool)

    if not n:
        return {}
    if n == 1:
        return {1: [base]} #  The basic case.
    else:
        bottom_row = list()
        prev_p = pascal(n-1, base) #  Only do one recursive call!
        for i in range(0, n):
            if i == 0:
                bottom_row.append(prev_p[n-1][i])
            elif i == n-1:
                bottom_row.append(prev_p[n-1][i-1])
            else:
                bottom_row.append(prev_p[n-1][i-1]+prev_p[n-1][i])
        bottom_row = {n: bottom_row}
        pascal_dict = prev_p
        pascal_dict.update(bottom_row)
        return pascal_dict

标签： pythonassertionisinstance

解决方案

没有矢量化的isinstance.

assert isinstance((n, base), (int, int))

应该

assert isinstance(n, int) and isinstance(base, int)

如果你有大量的变量......

for var in [n, base, count, blah, foo, bar]:
    assert isinstance(var, int)

如果您不需要对它们进行单独维修：

assert(all(isinstance(var, int) for var in list))

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