replace %(word) in a string
christophe.delord at free.fr
Wed Sep 17 22:14:50 CEST 2003
On 17 Sep 2003 16:30:08 GMT, Fred Pacquier wrote:
> Mirko Zeibig <mirko-lists at zeibig.net> said :
> > Especially useful together with the locals() function, which returns
> > a dictionary of locally defined variables:
> > def foo():
> > a = "Hello"
> > b = "World"
> > print "%(a)s %(b)s" % locals()
> Yes, that's a wonderful feature. Recently though, I've wondered a
> couple of times : is there an easy way to substitute with both local
> AND global variables ?...
You can substitute local and global variables. But you can do much more.
You can write a python expression in %(...)s if the object on the right
side of % looks like a dictionnary and can evaluate its argument. For
example I often this piece of code:
def __getitem__(self, item):
frame = sys._getframe(1)
return eval(item, frame.f_globals, frame.f_locals)
As I only need one instance of I, I use:
I = I()
Then I can write thing like that:
word1 = "python"
word2 = "lovers"
print "Hello, %(word1)s %(word2)s !"%I
print "1 + 1 = %(1+1)s"%I
But you must keep in mind that the use of eval may not be safe.
(o_ Christophe Delord __o
//\ http://christophe.delord.free.fr/ _`\<,_
V_/_ mailto:christophe.delord at free.fr (_)/ (_)
More information about the Python-list