实操一下<python cookbook>第三版1

青旅半醒 2021-09-30 07:40 322阅读 0赞

这几天没写代码，

练一下代码。

找的书是<python cookbook>第三版的电子书。

\*这个操作符，运用得好，确实少很多代码，且清晰易懂。

![465438-20181105113130474-296410296.png][]

p = (4, 5)
    x, y = p
    print(x)
    print(y)
    
    s = 'Hello'
    a, b, c, d, e = s
    print(a, b, c)
    
    data = ['ACME', 50, 91.1, (2012, 12, 21)]
    _, shares, price, _ = data
    print(shares, price)
    
    def drop_first_last(grades):
        first, *middle, last = grades
        return middle
    
    print(drop_first_last([23, 34, 45, 56, 67, 78, 12, 23]))
    
    record = ('Dave', 'dave@example.com', '773-555-1212', '847-555-1212')
    name, email, *phone_numbers = record
    print(name, email, phone_numbers)
    
    *trailing_qtrs, current = [10, 8, 7, 1, 9, 5, 10, 3]
    trailing_avg = sum(trailing_qtrs) / len(trailing_qtrs)
    
    print(current, trailing_avg)
    
    records = [
        ('foo', 1, 2),
        ('bar', 'hello'),
        ('foo', 3, 4),
    ]
    
    def do_foo(x, y):
        print('foo', x, y)
    
    def do_bar(s):
        print('bar', s)
    
    for tag, *args in records:
        if tag == 'foo':
            do_foo(*args)
        elif tag == 'bar':
            do_bar(*args)
    
    
    line = 'nobody:*:-2:-2:Unprivileged User:/var/empty:/usr/bin/false'
    uname, *fields, homedir, sh = line.split(':')
    print(uname, homedir, sh)
    
    record = ('ACME', 50, 123.45, (12, 18, 2012))
    name, *_, (*_, year) = record
    print(name, year)
    
    items = [1, 10, 7, 4, 5, 9]
    head, *tail = items
    print(head, tail)
    
    def sum(items):
        head, *tail = items
        return head + sum(tail) if tail else head
    print(sum(items))

输出：

4
    5
    H e l
    50 91.1
    [34, 45, 56, 67, 78, 12]
    Dave dave@example.com ['773-555-1212', '847-555-1212']
    3 7.142857142857143
    foo 1 2
    bar hello
    foo 3 4
    nobody /var/empty /usr/bin/false
    ACME 2012
    1 [10, 7, 4, 5, 9]
    36
    
    Process finished with exit code 0

转载于:https://www.cnblogs.com/aguncn/p/9908181.html

[465438-20181105113130474-296410296.png]: /images/20210725/31f9b98e230f4fed83189dee3ed0c992.png