002_029 Python 带版本号的文件名,给文件加上类00i的版本号

代码如下：

#encoding=utf-8

print '中国'

#带版本号的文件名
import os
def VersionFile(file_spec, vtype='copy'):
    import os, shutil
    if os.path.isfile(file_spec):
        if vtype not in ('copy','rename'):
            raise ValueError,'Unknown vtype %r' %(vtype,)
        n, e = os.path.splitext(file_spec)
        if len(e) == 4 and e[1:].isdigit():
            num = 1 + int(e[1:])
            root = n
        else:
            num = 0
            root = file_spec
        for i in  xrange(num,1000):
            new_file = '%s.%03d' %(root,i)
            if not os.path.exists(new_file):
                if vtype == 'copy':
                    shutil.copy(file_spec, new_file)
                else:
                    os.rename(file_spec, new_file)
                return True
        raise RuntimeError,'Failed'
    return False

testfile = 'test.abc'
open(testfile,'w').close()

print VersionFile(testfile)
print VersionFile(testfile)
print VersionFile(testfile)

for x in ('','.000','.001','.002'):
    os.unlink(testfile + x)
print VersionFile(testfile)

打印结果如下：

中国
True
True
True
False