Python 基础知识整理 - 标准库简介（3）

# 日期构造以及格式化
from datetime import date
now = date.today()
print(now)
print(now.strftime("%m-%d-%y. %d %b %Y is a %A on the %d day of %B."))
print(now.strftime('%Y{y}%m{m}%d{d}').format(y='年', m='月', d='日'))


# 支持日历计算
birthday = date(1964, 7, 31)
age = now - birthday
print(age.days)
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2022-01-01
01-01-22. 01 Jan 2022 is a Saturday on the 01 day of January.
2022年01月01日
20973
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import zlib


s = b'witch which has which witches wrist watch'
print(len(s))


t = zlib.compress(s)
print(t)
print(len(t))


print(zlib.decompress(t))


print(zlib.crc32(s))
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41
b'x\x9c+\xcf,I\xceP(\xcf\xc8\x04\x92\x19\x89\xc5PV9H4\x15\xc8+\xca,.Q(O\x04\xf2\x00D?\x0f\x89'
37
b'witch which has which witches wrist watch'
226805979
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from timeit import Timer


print(Timer('t=a; a=b; b=t', 'a=1; b=2').timeit())
print(Timer('a,b = b,a', 'a=1; b=2').timeit())
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def average(values):
    """Computes the arithmetic mean of a list of numbers.


    >>> print(average([20, 30, 70]))
    40.0
    """
    return sum(values) / len(values)


import doctest
print(doctest.testmod())   # 自动验证嵌入的测试
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TestResults(failed=0, attempted=1)
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Failed example:
    print(average([20, 30, 70]))
Expected:
    30.0
Got:
    40.0
**********************************************************************
1 items had failures:
   1 of   1 in __main__.average
***Test Failed*** 1 failures.
TestResults(failed=1, attempted=1)
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import unittest


def average(values):
    return sum(values) / len(values)


class TestStatisticalFunctions(unittest.TestCase):


    def test_average(self):
        self.assertEqual(average([20, 30, 70]), 40.0)
        self.assertEqual(round(average([1, 5, 7]), 1), 4.3)
        with self.assertRaises(ZeroDivisionError):
            average([])
        with self.assertRaises(TypeError):
            average(20, 30, 70)


unittest.main()
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.
----------------------------------------------------------------------
Ran 1 test in 0.000s


OK
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