modifying string objects

[Gerhard Häring]

Uwe Mayer wrote in comp.lang.python:
> hi,
> 
> strings are immutable in python. so what do i do if i need to pass a 
> function a string as parameter and need it to be modified within the 
> function so that changes are reflected outside of the function body?

You _could_ use a mutable wrapper object, like a custom class or
simply a list, like in:

def add_an_a(swrap):
    swrap[0] = swrap[0] + "a"

x = ["b"]
add_an_a(x)
print x[0]

But it's generally much better to just let the function return the new
value, as in:

def add_an_a(s):
    return s + "a"

print add_an_a("b")

HTH,

Gerhard
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reduce(lambda x,y:x+y,map(lambda x:chr(ord(x)^42),tuple('zS^BED\nX_FOY\x0b')))