如何在Python中增加文件名

Question

我正在尝试将大量需要分离的数据保存到不同的文件中 data_1.dat data_2.dat data_3.dat data_4.dat

我如何在python中实现它？

Answer 1

from itertools import count
filename = ("data_%03i.dat" % i for i in count(1))
next(filename)
# 'data_001.dat'
next(filename)
# 'data_002.dat'
next(filename)
# 'data_003.dat'

Answer 2

for i in range(10):
    filename = 'data_%d.dat'%(i,)
    print filename

Answer 3

与Sven的解决方案类似，但升级到完整的生成器：

from itertools import count
def gen_filenames(prefix, suffix, places=3):
    """Generate sequential filenames with the format <prefix><index><suffix>

       The index field is padded with leading zeroes to the specified number of places
    """
    pattern = "{}{{:0{}d}}{}".format(prefix, places, suffix)
    for i in count(1):
        yield pattern.format(i)

>>> g = gen_filenames("data_", ".dat")
>>> for x in range(3):
...     print(next(g))
... 
data_001.dat
data_002.dat
data_003.dat

Answer 4

如果你采用itertools方式，为什么要将它与生成器表达式混合使用？

>>> import itertools as it
>>> fngen= it.imap("file%d".__mod__, it.count(1))
>>> next(fngen)
'file1'