Question

我有......

>>> for i in range(11):
...     for j in range(103):
...             print "./", '%02d' % i, "/IMG", '%04d' % j, ".jpg"
...
>>> (prints a whole bunch of lines representing files in a group of directories)

...而我想要的是将这些行中的小字符串和整数连接成单个字符串，并将其附加到一个列表中，该列表将包含大约1100个元素，每个元素都是文件的名称。我该如何修改循环？

Answer 1

ITYM

l = []
for i in range(11):
    for j in range(103):
        l.append()

或更短，

l = ['./%02d/IMG%04d.jpg' % (i, j) for i in range(11) for j in range(103)]

Answer 2

['./%02d/IMG%04d.jpg' % (i, j) for i in range(11) for j in xrange(103)]

Answer 3

from itertools import product
['./%02d/IMG%04d.jpg'%item for item in product(range(11),range(103))]

或稍微（~6％）更快但更混淆

 map('./%02d/IMG%04d.jpg'.__mod__, product(range(11),range(103)))


$ python -m timeit -s"from itertools import product" "['./%02d/IMG%04d.jpg'%item for item in product(range(11),range(103))]"
1000 loops, best of 3: 1.56 msec per loop

$ python -m timeit -s"from itertools import product" "map('./%02d/IMG%04d.jpg'.__mod__, product(range(11),range(103)))"
1000 loops, best of 3: 1.46 msec per loop

如何将此python打印函数的每一行写入字符串列表？

3 个答案: