Python - 如何使用%s修改文本输出？

Question

非常直接给你们,但你如何修改%s的输出值？

print "Successfully created the file: %s" % iFile + '.txt'

我尝试使用()的,{}的,但没有什么工作？

iFile是文件的名称,我希望它在显示时以.txt显示.

编辑:

我得到了输出 Successfully created the file: <open file 'test', mode 'rb' at 0x14cef60>.txt

Answer 1

用途str.format(*args, **kwargs:

"Successfully created the file: {0}.txt".format(iFile)

例:

In [1]: iFile = "foo"

In [2]: "Successfully created the file: {0}.txt".format(iFile)
Out[2]: 'Successfully created the file: foo.txt'

编辑

由于您似乎有一个文件,而不是文件名,您可以这样做:

In [4]: iFile = open("/tmp/foo.txt", "w")

In [5]: "Successfully created the file: {0}.txt".format(iFile)
Out[5]: "Successfully created the file: <_io.TextIOWrapper name='/tmp/foo.txt' mode='w' encoding='UTF-8'>.txt"

In [6]: "Successfully created the file: {0}.txt".format(iFile.name)
Out[6]: 'Successfully created the file: /tmp/foo.txt.txt'

请注意,现在输出foo.txt.txt具有双扩展名.如果您不希望这样,因为文件的名称已经存在foo.txt,则不应打印其他扩展名.

使用%是格式化字符串的旧方法.当前的Python教程format详细解释.