Question

我创建的代码基本上生成一个随机的20位数字。代码如下：

import random
from random import randint

n=20

def digit(n):

    range_start = 10**(n-1)
    range_end = (10**n)-1
    return randint(range_start, range_end+1)


print(digit(n))

此代码的输出例如是：

49690101904335902069

现在给出这段代码，我只是想知道如何计算输出中的零数，所以基本上我正在尝试创建一个名为count_zero():的新函数，但我不知道什么把它放在我的参数和什么没有。

Answer 1

将数字转换为字符串并计算'0'个字符的数量：

def count_zeros(number):
    return str(number).count('0')

演示：

>>> def count_zeros(number):
...     return str(number).count('0')
... 
>>> count_zeros(49690101904335902069)
5

或者不将其变成字符串：

def count_zeros(number):
    count = 0
    while number > 9:
        count += int(number % 10 == 0)
        number //= 10
    return count

后一种方法是 lot 然而慢：

>>> import random
>>> import timeit
>>> test_numbers = [random.randrange(10 ** 6) for _ in xrange(1000)]
>>> def count_zeros_str(number):
...     return str(number).count('0')
... 
>>> def count_zeros_division(number):
...     count = 0
...     while number > 9:
...         count += int(number % 10 == 0)
...         number //= 10
...     return count
... 
>>> timeit.timeit('[c(n) for n in test_numbers]',
...     'from __main__ import test_numbers, count_zeros_str as c', number=5000)
2.4459421634674072
>>> timeit.timeit('[c(n) for n in test_numbers]',
...     'from __main__ import test_numbers, count_zeros_division as c', number=5000)
7.91981315612793

要将其与您的代码结合使用，只需添加该功能，然后分别调用;您可以直接传递digit()的结果或先存储结果，然后将其传递给：

print(count_zeros(digit(n)))

或单独（允许您显示结果随机数）：

result = digit(n)
zeros = count_zeros(result)
print('result', result, 'contains', zeros, 'zeros.')

Python计数零

1 个答案: