如果一个可迭代对象的元素个数超过变量个数时，会抛出一个ValueError。那么怎样才能从这个可迭代对象中解压出N个元素出来？
Python 提供“*”号表达式解决该问题
#示例1 >>> record = ('Dave', 'dave@example.com', '773-555-1212', '847-555-1212') >>> name, email, *phone_numbers = record >>> name 'Dave' >>> email 'dave@example.com' >>> phone_numbers ['773-555-1212', '847-555-1212'] >>> #示例2 >>> *trailing, current = [10, 8, 7, 1, 9, 5, 10, 3] >>> trailing [10, 8, 7, 1, 9, 5, 10] >>> current 3 #示例3 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) #示例4 >>> line = 'nobody:*:-2:-2:Unprivileged User:/var/empty:/usr/bin/false' >>> uname, *fields, homedir, sh = line.split(':') >>> uname 'nobody' >>> homedir '/var/empty' >>> sh '/usr/bin/false' >>> #示例5 #有时候，你想解压一些元素后丢弃它们，你不能简单就使用 * ，但是你可以使用一个普通的废弃名称，比如_或者_ign >>> record = ('ACME', 50, 123.45, (12, 18, 2012)) >>> name, *_, (*_, year) = record >>> name 'ACME' >>> year 2012