Like *nix's {{{tr}}} (in Python 3)
{{{c
"Hello World".translate(str.maketrans("lo","XY"))
# returns: "HeXXY WYrXd"
}}}

Stuff that *nix's {{{tr}}} can't do:
{{{c
a = "Hello World"
d = {ord('l'):'Boing',ord('o'):'Snarf'}
a.translate(d)
# returns: "HeBoingBoingSnarf WSnarfrBoingd"
}}}

To see what {{{str.maketrans}}} does:
{{{c
str.maketrans("lo","XY")
# returns: {108: 88, 111: 89}
}}}
the //keys// need to be integer character codes. You go from character code to string via {{{chr()}}} and from character to character code via {{{ord()}}}. The //values// can be either integers (character codes), or strings, or None if you want to delete characters.
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