Python，在列表中的每个项目上附加字符串

Question

I have a code that concatenates a string 'lst' on each item of the list.

    i = 0
    lim = len(lst)
    while i < lim:
        lst[i] = 'lst%s' % (lst[i])
        i += 1

Is there a faster way of doing this?

Answer 1

This will modify the original lst object:

lst[:] = ['lst%s' % item for item in lst]

or using the new style string formatting:

lst[:] = ['lst{}'.format(item) for item in lst]

Answer 2

使用列表推导切片分配：

lst[:] = ['lst' + x for x in lst]

Answer 3

这是一个地图版本

lst = map(lambda x: 'lst%s' % x, lst)

Answer 4

A map version for fun

>>> lst=['foo', 'bar', 'baz']
>>> map('lst'.__add__, lst)
['lstfoo', 'lstbar', 'lstbaz']

But more seriously, you can assign to a slice from a generator expression

>>> lst[:] = ('lst{}'.format(x) for x in lst)
>>> lst
['lstfoo', 'lstbar', 'lstbaz']