复制代码 代码如下:

If order does not matter, you can use

"".join(set(foo))

set() will create a set of unique letters in the string, and "".join() will join the letters back to a string in arbitrary order.

If order does matter, you can use collections.OrderedDict in Python 2.7:

from collections import OrderedDict

foo = "mppmt"

print "".join(OrderedDict.fromkeys(foo))

printing

mpt